I agree with aquariangt and C4D, this is a horrible idea for a dog with fear-aggression. If a dog is about to bite, it means that they are at a fear level so high that they feel the need to physically defend themself. By rolling a dog over on their side, also called an alpha rollover, you are making the dog associate the situation with being forcefully and painfully rolled over on their side by the one person they thought they could trust. This may accomplish:
1. Making the dog more afraid and more likely to bite in a similar situation in the future.
2. Making the dog afraid of the owner.
3. Making the dog bite the owner.
Even though aggression may look different than what most people think of fearful behavior, it is almost always rooted in fear. I think it was perfectly reasonably for Sam to ask the girl to remove her raincoat, though it was reasonable for her mom to deny, as that is her choice.
