Oh boy, no. Our two vets back home would never let us leave them unattended with one of our dogs. I train/handle high level guardians. I've also given classes at the University Animal teaching hospital on dog aggression. So generally when I go to the clinic, the vet techs stay out of the way & are told to observe & learn. They loved it when one of our tiny dogs came in because those they were comfortable with. Then they learned just how trained my crew was & we became their favorite clients & were their go to trainer for clients.
Perhaps things were different back when that book was written but for those with guardians, it's part of the training not to allow anyone not living in the home to really handle the dogs. So the dogs are taken off property unless it's life/death emergency. I don't want my dogs to accept a stranger manipulating them on property. Their job there is priority. So for guardians, that's the training it's not about being spoiled or pampered.

On the other hand when we had a dog go to university for an MRI they were astonished when my husband handed the leash to a technician & instructed him on everything he would need to do. "Hup" to get up on the exam table. "Plutz" to have her lay down. "Over" to get her onto her side. "Blieb" for stay. Then take the leg & put it how you want it & tell her "hold". So long as he had the leash in hand she would do whatever he told her. They video taped it to show people it could be done. Our dogs never had to be sedated for x-rays or MRIs. Highly trained guardians could be handed over to the staff & managed without anyone knowing they were guardians.
Basically, I don't trust people too much with my dogs. I am always within hearing distance & likely have an eye on the proceedings or it's a no go as I had a dog abused by a vet, caught him in the act.