I don't see a reason to file for a divorce unless it was something that was already on the horizon. But taking the pictures seems cruel, but once they try and sue, and they will, they will need proof of her injuries and that the animals did actually attack her. So while in the moment it seems a very nasty and mean thing to do, but looking at the big picture he was documenting the attack for the lawyers!!!
There is no grounds for divorce! If he had tried to help, then he would have placed his life in danger; also because he is not trained to handle a situation like that.
The lawyer is going to need pictures.