As far as a rotating compass card, what Hichen saw was a rotating card caused by the ship along with him turning to port. The description used the ship as the frame of reference., just like Murdoch and the lookouts saw an iceberg approaching them, when it was them approaching an iceberg.
Or you could have said that the berg altered course to port toward Titanic starboard side and while the stern was veering to port after the allision, the pole star moved to westward in front of Titanic!
Samuel, we are talking about a brand new liner outfitted with the very best British main and standard maritime compasses. These compasses were fully adjusted, their bowl completely filled by the exact anti-damping and antifreeze liquid of specific density, their cards made significantly smaller in diameter than the bowl to minimize swirl error, the card oscillation could not have happened since the vessel was sailing in a sea as flat as a mirror, heeling deviation only occur at large angle, oscillation effects are maximum on north and south headings and so on. We are thus very far from a piper magnetic compass.
Nevertheless, when a vessel is turn for maximum rate of turn and steady with a sudden hard over counter wheel, the inertia of the card along with the insidious liquid movement, will make the compass card to overshoot the terrestrial magnetic field horizontal and directional component. But swiftly afterward, the magnetic moment created will force back the card to line up again. Samuel, I own 2 commercial vessel magnetic compasses. I have made a dozen turns with one on them this morning, some at unattainable rate of turn for a vessel, to port and to starboard, on a north/south and east/west initial heading. When the card was stable and lined up to the magnetic field, I turned the compass 45° to 90° to a desire appoint and repeated the experience. On any initial steady heading followed by the swing the compass, the card remained entirely fix whereas the lubber’s line was unambiguously seen veering or backing in the proper direction. When you stop swinging, the compass card keeps swinging to angles proportional of the rate of turn. If you swing slow, the compass card overshoots to a few insignificant degrees away from the desired steady lubber’s line, and then settles back. But if you swing very rapidly, the compass card overshoots the desire new steady heading to about twice that few degrees. Really nothing to be concerned about; just imagine what would have been the consequences in channels if it would not have been the case!
Therefore, when Hichens confirmed the wheel hard over, as a capable quartermaster he was watching the lubber’s line backing unmistakably to port, certainly not the compass card veering to starboard! The only thing he could then do if trained for, is to call every point that were decreasing by, which was apparently not the case....