Although English is the maritime language, the language proficiency of the watch crew on the merchant vessel could be an issue but if the Fitzgerald had its AIS off and it was 2:30am so Fitzgerald's ship number may not have been visible which would add some confusion for a watch member with limited English proficiency attempting to communicate on VHF 16. How closely is English proficiency for watch crew monitored by commercial merchant ship operators? As you say, this will all be figured out by the inquiry eventually.
It will be figured out by the enquiry, however AIS is not the end all to collision avoidance. In any conditions, and in close proximity, the collision avoidance rules of the COLREG convention take precedence (I understand the conditions were clear).
Communication will not always resolve the issues if the messages are confused and this happens with English speaking mariners as well.
Both parties are required to take action to avoid collision (this includes the stand on vessel) and alterations of course are to be large enough to be clear visible. If the other vessel was all over the shop they will be held to account. The track leading up to the close quarters situation will need to be examined and we (and G Captain) should not be jumping to conclusions.
One of the big issues we have at the moment is the habit of mariners to stick their heads into the radar or integrated display and not
look out the window and take bearings of the other vessel. When it gets close visual bearing movement and vessel orientation (which is why we have navigation lights). If your display is not showing relative movement you could find yourself in trouble.