Rostron said quite a few odd things. He said that the vessel showing the red light was between him and Titanic (Boxall). The point here is that if Californian was heading West at that time, then her red light would be shut-out to vessels in the direction of Carpathia. Additionally, it could never have been Californian if she was NW of Boxhall. Not only that, there is no way on God's green earth that her red side light would have been visible, with or without binoculars to anyone on Carpathia...even if she had only been 10 miles NW of Boxhall at that time.It's rather odd that Stone talks of a vessel seen bang on the port beam (due south with Californian facing due west) at 0400 when at a similar time Carpathia sees a vessel bearing N30W true from Boxhall's boat.
Any vessel to the south of Californian at 4 am that morning, had to be on the west side of the ice barrier unless it was trending Noth-South (which it was not at that point). There is no way the vessel in question could have been Carpathia. If anything, it was more than likely to have been the Mount Temple. She was the only vessel around at that time with a yellow (buff)funnel. In fact, if Mount Temple stopped 10 miles South of the Californian at just before 4 am that morning, she would have been bearing N30 W from Carpathia at or near to the time the latter arrived near to Boxhall.