You are definately not being over protective. I personally would have been furious and would have confronted the groomers as well as the person who was holding her and told them straight out that such a thing is not only rude but inappropriate. She is your dog and you are paying for a service and they were
completely out of line for handing around your girl. Not only was there the risk of her being stolen but what if she had riggled free and fallen and been hurt? Ahem, we all know
they wouldn't be willing to pay the vet bills to fix her injuries so they shouldn't be holding her w/o your consent. And another risk is what if your girl felt scared and decided she didn't like this person and bit and hurt them and wow.. guess what.. Once again you'll be the one paying when they throw a lawsuit in your face and you could even lose your little girl bc of this. I mean the risks are endless.
WARNING NOTICE OF
KINDA FALLING OFF TOPIC
I've only had professionally groomed once and it was quite an ordeal. I don't know if they 'passed him around'.. God only knows.. but the lady did a terrible job, sprayed him w/ that mens deoderant "Axe" (which made him sneeze, itch insanely) and she jumped up the final price an extra 10 bucks (gave herself a tip) when she saw me pull out a couple fifty dollar bills. Needless to say I called back and b*tched and still have that $10 store credit there waiting.. But doubt that will ever happen since they burnt the you know what out of my other dogs belly!