What you have is a group of punks that have decided to harass the Japanese.
They throw ropes meant to entangle propelers and jam rudders. They throw stink bombs ( kind of similar to a Mustang GT) onto the Japanese ships.
The Japanese have been challenged in International court and they are found to be compliant with international regulations. This group of stupid misfits can't handle that so they intentionally try to damage the Japanese ships.
Watching both videos you get a good idea of what happened. The Japanese Captain decided to get in close to the Ady Gil and harass it back. At the same time the Japanese ship moved to the right, starboard, the Ady Gil decided it wanted to get closer too and moved forward. The Japanese ship clearly steers hard to port as it becomes evident that the Ady Gil is moving into her new path. The Ady Gil is unable stop or turn quick enough.
Plain and simple, if I was the Captain of of the Japanese ship and was having ropes meant to disable my ship and put my crew in harms way and stink bombs thrown at me I think I would have rammed the punks too.
Good for the Japanese fleet. Unfortunately these idiots probably haven't learned from this and they wil get sympathy because all they are trying to do is save a whale.