This could be construed as to mean Lightoller dove off the Titanic from directly amidships the officer’s quarters. However, he could not have done so due to one little detail:
The huge blowers that were placed aft of the roof of the Titanic’s bridge atop the officer’s quarters. The selfsame blowers that Lightoller was pinned against while attempting to swim away from the ship.
They would have blocked his path had he attempted to dive off from right amidships atop the deckhouse.
What is more, Lightoller added after saying "practically midships" that he was "a little to the starboard side, where I had got to [Emp added]". Meaning he had been en route to help Murdoch at Collapsible A when he stopped short on the starboard side of the officer’s quarters.

 Lightoller’s statements before Senator Smith as to what he saw before the final plunge fully bears out his British Inquiry testimony:

 Senator SMITH. From what point on the vessel did you leave it?
 Mr. LIGHTOLLER. On top of the officers' quarters.
 Senator SMITH. And where were the officers' quarters?
 Mr. LIGHTOLLER. Immediately abaft the bridge.
 Senator SMITH. Immediately abaft the bridge?
 Mr. LIGHTOLLER. Abaft the wheelhouse.
 Senator SMITH. Was that pretty well toward the top of the vessel?
 Mr. LIGHTOLLER. Yes, sir.
 Senator SMITH. Were the lifeboats gone when you found yourself without any footing?
 Mr. LIGHTOLLER. All except one.
 Senator SMITH. Where was that one?
 Mr. LIGHTOLLER. In the tackles, trying to get it over.
 Senator SMITH. Did not the tackle work readily?
 Mr. LIGHTOLLER. Yes, sir.
 Senator SMITH. What delayed it?
 Mr. LIGHTOLLER. It was the third boat over by the same tackles.
 Senator SMITH. The third boat over by the same tackles?
 Mr. LIGHTOLLER. Yes, sir.
 Senator SMITH. From what deck?
 Mr. LIGHTOLLER. The boat deck.
 Senator SMITH. The sun deck?
 Mr. LIGHTOLLER. The sun deck.
 Senator SMITH. How close were you to this lifeboat at that time?
 Mr. LIGHTOLLER. Fifteen feet
 Senator SMITH. Was it filled before starting to lower it?
 Mr. LIGHTOLLER. It was not high enough to lower.
 Senator SMITH. Why?
 Mr. LIGHTOLLER. It was not high enough to lower. They were endeavoring to get it over the bulwarks, outboard; swinging it; getting it over the bulwarks. When it was over the bulwarks, then it would hang in the tackles, and until it hung in the tackles it was impossible to put anyone in it.
 Senator SMITH. How far below the boat deck?
 Mr. LIGHTOLLER. Above the boat deck.
 Senator SMITH. How far above the boat deck?
 Mr. LIGHTOLLER. About 4 feet 6 inches.
 Senator SMITH. And it was lowered to the boat deck?
 Mr. LIGHTOLLER. It did not get over the bulwarks to be lowered.
 Senator SMITH. The last you saw of it?
 Mr. LIGHTOLLER. Yes, sir.
 Senator SMITH. Who was managing this tackle?
 Mr. LIGHTOLLER. The first officer, Mr. Murdoch.
 Senator SMITH. He lost his life?
 Mr. LIGHTOLLER. Yes.

 And later affirmed:

 Senator SMITH. You say you were 15 feet from this last boat when it was lowered?
 Mr. LIGHTOLLER. It was not lowered, sir. I was 15 feet from it when they were endeavoring to get it into the tackles.
 Senator SMITH. Did you go nearer to it than that.
 Mr. LIGHTOLLER. Did not have the opportunity, sir.
 Senator SMITH. Why not?
 Mr. LIGHTOLLER. The ship went down.
 Senator SMITH. Was this boat ever lowered?
 Mr. LIGHTOLLER. No, sir.
 Senator SMITH. It remained in the tackle?
 Mr. LIGHTOLLER. Yes, sir.

 And affirmed yet again:

 Senator SMITH. Did you see Mr. Murdoch after that?
 Mr. LIGHTOLLER. Yes, sir; I saw him when I came out of the quarters after the impact.
 Senator SMITH. Where was he?
 Mr. LIGHTOLLER. On the bridge.
 Senator SMITH. With the captain?
 Mr. LIGHTOLLER. One on one side, and one on the other side of the bridge; one on each side.
 Senator SMITH. Did you speak to him after that?
 Mr. LIGHTOLLER. No, sir.
 Senator SMITH. I mean after he took the watch?
 Mr. LIGHTOLLER. No, sir.
 Senator SMITH. You never spoke to him again?
 Mr. LIGHTOLLER. No; sir.
 Senator SMITH. You were not together when finally parted from the ship?
 Mr. LIGHTOLLER. No, sir.
 Senator SMITH. You saw him on the bridge at the time?
 Mr. LIGHTOLLER. Immediately after the impact; yes, sir.
 Senator SMITH. Did he remain there until the end?
 Mr. LIGHTOLLER. He was getting the boats out on the starboard side later on.
 Senator SMITH. Later?
 Mr. LIGHTOLLER. Yes, sir.
 Senator SMITH. Did you see him at that work?
 Mr. LIGHTOLLER. No, sir; I was on the port side.
 Senator SMITH. How do you know that he did it?
 Mr. LIGHTOLLER. I saw him at the last boat

 And when asked once more on this point:

 Senator SMITH. Do you know who had charge on the starboard side of the lowering and filling of the boats?
 Mr. LIGHTOLLER. No, sir. Merely what I am told.
 Senator SMITH. What have you been told about it. May be we can get something from that.
 Mr. LIGHTOLLER. As far as I know, and I think it is correct, Mr. Murdoch. Mr. Murdoch was on the starboard side. I was on the port side, and Mr. Murdoch was on the starboard side, and the chief officer was superintending generally, and lowered one or two boats himself.
 Senator SMITH. From whom did you get information?
 Mr. LIGHTOLLER. Of course, I saw Mr. Murdoch there when finally I had finished on the port side.
 Senator SMITH. You went to the starboard side?
 Mr. LIGHTOLLER. On top; yes, sir.
 Senator SMITH. For the purpose of lowering this -
 Mr. LIGHTOLLER. I went over to see if I could assist.
 Senator SMITH. And you saw him there?
 Mr. LIGHTOLLER. I saw him there.

 In Lightoller’s American testimony he tells exactly how far he was from Collapsible A: Fifteen feet. Which from his perch on the officer’s quarters was enough room for him to have seen everything. Indeed, would have been, as he wrote to Ada Murdoch "practically looking down" on them.
 In light of the above facts, the doubts cast as to Lightoller’s word based upon his statement about being "practically amidships" at the time of the final plunge are needless. 3

Final Summary

 What does this all mean as far as the officer’s suicide enigma is concerned?
 First, the fact George Rheims was not at Collapsible A when the end came makes one wonder just what exactly it was he saw, and where. As well as casts serious doubt on the possibility that it was at Collapsible A, given Rheims’ absence from that boat.
 As far as Charles Lightoller is concerned, his word is unimpeachable. Given how his three accounts from immediately after the sinking match perfectly.
 Indeed, despite researcher Suzanne Stormer’s discovery some years ago that Lightoller allegedly admitted later in life that he knew someone who took their life aboard ship during the sinking, Lightoller’s eyewitness account as to Murdoch’s end, to my mind at any rate, puts Murdoch in the clear as to wether or not his death was a suicide.
 In closing, the whole officer’s suicide enigma is one which is wrapped in layer upon layer of riddle.
Hopefully, the deductions made in this article as to Rheims and Lightoller’s evidence slices through at least one of those layers.

Notes

1. This is a slightly different translation than the one available to Walter Lord when he wrote The Night Lives On. It can be read in it’s entirety at Bill Wormstedt and Tad Fitch’s "Shots In The Dark" website where can also be found the complete text of Lightoller’s letter to Ada Murdoch.
 
2. Could Rheims have heard First Officer Murdoch firing his pistol at Collapsible C?
 Consider the evidence of Hugh Woolner at the American inquiry:

 Mr. WOOLNER. Then they eventually lowered all the wooden lifeboats on the port side, and then they got out a collapsible and hitched her onto the most forward davits and they filled that up, mostly with steerage women and children, and one seaman, and a steward, and I think one other man - but I am not quite certain about that - and when that boat seemed to be quite full, and was ready to be swung over the side, and was to be lowered away, I said to Steffanson: "There is nothing more for us to do here." Oh, no; something else happened while that boat was being loaded. There was a sort of scramble on the starboard side, and I looked around and I saw two flashes of a pistol in the air.
 Senator SMITH. Two flashes of a pistol?
 Mr. WOOLNER. Yes.
 Senator SMITH. Pistol shots?
 Mr. WOOLNER. Yes; but they were up in the air, at that sort of an angle [indicating]. I heard Mr. Murdoch shouting out, "Get out of this, clear out of this," and that sort of thing, to a lot of men who were swarming into a boat on that side.

 Woolner’s number of pistol shots matches Rheims number exactly and Collapsible C was lowered away roughly forty minutes before the Titanic sank. Thus Rheims could have been within earshot of this event at the same time Woolner was.
 It also begs the question: Could Rheims have seen Murdoch firing his pistol in the air at Collapsible C, during which Murdoch also threw the men in question out of the boat, and somehow came away with a mistaken impression about shootings and, somehow, a suicide?
 Unless Rheims’ liability court testimony from the stand is ever uncovered, we will never know for sure.

3. Lightoller only devotes one sentence in his book Titanic and Other Ships to his crossing between the port and starboard sides of the ship before the end came, saying simply:

Hemming and I then, as every single boat was away from the port side, went over to the starboard side, to see if there was anything further to be done there. (Titanic and Other Ships, Chapter 34, page 132)

 Lightoller’s memory was off as to one detail in that lamp trimmer Samuel Hemming did not accompany him across the deck house. Hemming having already assisted with Collapsible A and was at the time Lightoller went to try to help Murdoch already making his escape from the doomed vessel.
 However, despite this flaw in Lightoller’s memory, his book nonetheless also corroborates his final movement aboard ship.

 For those curious to read Rheims’ depostion and Lightoller’s testimony in their entirely, consult the Titanic Inquiry Project website.

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