I also wanted to offer you my deepest condolences.
Personally, I would, at the very least, bring this unfortunate event to the attention of the Board of Veterinarians. You can also ask if there have been other complaints filed against him and, perhaps, that may help you decide how to proceed.
I 100% agree with this logic. If this vet has a history of complaints against him/her - then yes I would likely pursue the matter further. If the vet has no such history (which would suggest to me that this is mostly an accident) I would likely not pursue it.
Again I'm so sorry to hear of this -