If this were to go to court or a citation written based only on the video, I think the smaller boat
has a good argument he was the stand on vessel and was certainly much less negligent than he larger give way vessel.
If one considers they were head
on, they should have passed port to port and from the video, it appears, he was trying to get into that position to do just that and to pass port to port. The large vessel should have turned to starboard to pass port to port which he clearly did not.
If the operator or the larger vessel claims they were not head
on, he still was the give way vessel as the smaller vessel was to his right, so the larger vessel should have either slowed down or changed course to starboard (as above).
It seems to me for the operator of the large vessel to claim he was not negligent or had lower comparative negligence, he would have to argue other conditions not apparent in the video applied. For example, maybe he was in a marked channel and the smaller vessel was cutting across the channel. Maybe the smaller vessel changed course just seconds before this video started. There are many other potentially relevant facts not in evidence. Did the large vessel shift to reverse? Were sound signals used? Was navigation
of the large vessel otherwise restricted? Did other local rules apply? One could go on and on about possible facts not in evidence.
I'll also point out that the outcomes of court cases and and insurance
claims do not always completely favor one party or the other. Comparative or contributory negligence may apply and people often settle claims somewhere in the middle ground.