In the first event, when the lady was checking out what was going on with the Shih Tzu and candy, did she reach into the Shih Tzu's mouth? Or did she place her hand over/across the dog's head?
She hadn't even touched the dog yet...So she jumped back and then saw what her dog was doing! I don't know what happened next besides a plain repremand of no eating that, no hitting, just a stern voice.

In the second event, when the lady wanted to move the Shih Tzu, did she make a sudden movement when the dog was groggy and sleepy?
I am not sure if she made a quick movement, but, the dog was wide awake. She could've made a quick movement that might of scared her a little bit...

Did she aquire this dog from a shelter? If so I'd have her check with them to see if the dog has any history of snappiness. And they should offer free advice & possibly classes.
Yes, she got this dog from the shelter. I know that they don't offer classes, I have checked for my friends dog that they got from there...I will let her know to call them and ask about her history in general!

Giselle, I think that I will get some printouts to give to her!

Thank you both, anyone else have any advice to add?-It would be appriciated

Steph and Jes