I still don't see how she thought the snake's jaw looked weak. Did she open the snake's mouth? Do X-Rays to observe bone density?

I would either get a second opinion, or just keep feeding your snake like you're doing. I wouldn't allow anyone to inject a Ca solution into your snake without doing radiographs, and diagnosing low bone mass/density. Just absolutely ridiculous...

Also, regardless of if Scotty's uncle puts the pills into the rat or into the snake, it is completely wrong and unnecessary. It is not known how much of each vitamin/mineral snakes require, and his giving the snake HUMAN pills will ultimately cause damage, possibly death, to the animal.