How much does he weigh right now, and what size rats were you feeding him?
I'd take him to a reptile vet, and I personally wouldn't continue asking this friend for advice/approval (even just based on her husbandry suggestions and actions). That rat looks WAY too large for him, and large prey can cause regurgitation. But that there were bones stuck in his throat sounds scary!
I would even wait 2 full weeks before offering food again, and see what the reptile vet says.
Be sure that the exotic vet is specifically experienced with snakes too... Some vets might say that they'll look at your ball python, but they don't actually know what they're doing or talking about.