The owner is clearly trying to blame the trainer...and it seems the trainer is just doing what she can to make the situation go away. If the owner were right- she wouldn't be focused on the trainer losing her reputation, or money, and she wouldn't have been riding the horse days after it was "injured". Plus- I'm a vet tech- and I'm pretty sure I've never seen "fresh" wounds look like that. Granted I work with dogs and cats- but horse injuries aren't THAT different.
It would be easy to take pictures of injuries AFTER there has been a revision of the wounds and then say they are "fresh".