They didn’t have to shoot them, they could have just released them...into the ocean.
You mean like make them walk the plank!
I'll bet the Russian Captain made the pirates 'walk the plank', after keel-hauling them of course.
You don’t understand, the Russians wanted their comrades to see them. Their death was not punishment, it was a message.
I would not be surprised to find out that the bodies had been mutilated in some meaningful way.