I was at this property several years ago, shot several beavers over a few nights until I had no more targets and didn't hear back from the landowner until recently. Sure enough, the beaver are back...

Nice shooting. Always enjoy your video's.

Any reason to not shoot again after the first hit?

I am not sure why you are asking. What would be the purpose to shoot again?

Seems like they were trying to swim away, a.k.a. not dead.

The leg flutter kick? That happens when they are upside down and dead. That is the same as the dirt dance or curly shuffle you may see hogs do. It is the disinhibition of the motor neurons after death.