aww, poor baby! That's just AWFUL!
I'm sure the manufacturer is just trying to give them the brush off. Looks like they have ample evidence, I would give them one more try at making right on this, if they choose to ignore the complaint, I would seek legal advice. You would think that they would choose the 'easiest' way out of this since they are clearly at fault.
I'm glad you are sharing this story. Hopefully, it will spare some other dogs of the same misfortune. I think I will pass this along to some friends/family in email. Thank you.