watching both videos, in the one from the whaler, I have a hard time distinguishing the movements of the ship, I think much of what I think is the ship maneuvering is the camera
moving / zooming... I'm pretty sure this is a handheld camcorder.
On the video from the Sea Shepherds, the whaler made an obvious turn to port after they hit the speedboat. I've never steered anything near that big, but I'm pretty sure it takes a little time for the helmsman's input on the wheel
to make the boat change direction.
I suppose they could've been steering
to the stern of the speedboat, until it stopped or began reversing. And then to port, but not soon enough. I can't really tell, and yes, this is an assumption biased on the thought that they were actively trying to avoid running the boat over.
Either way, if they were following any standards for maritime collision avoidance, the speedboat wouldn't have been right in front of the whaler to begin with.
But they should've shut off, or turned away the water
cannons once it was obvious they smashed the hell out of them.