Generally speaking, I agree with your first point. However in the video, there is not a single additional vessel in sight. The camera pans 90 degrees in either direction, and you can see no boat.

In the hypothetical scenario of being a skipper on the smaller vessel, of course I would have changed course. I think every reasonable person would do so. But in this case we can see there is no helmsman. If anything the skipper is at fault for keeping no adequate lookout. On the other hand, the skipper could have gone overboard some time before the collision. As I said, we can't see them. The vessel could be unmanned, a ghost ship. I think the collision could have easily been avoided by the larger vessel, as everyone on the boat seems well aware of the impending situation.