I've had bad luck with vet techs and receptionists, and occasionally vets themselves who just want to hustle through an appointment and get to the next one. For example, I've been to a couple different vets (I move around a lot) who will want to take my dog into the back, out of my sight, to do almost everything. While I can understand there are several good reasons they want to do this, it doesn't work for me or my dogs. I have one who is scared, but will calm right down for almost anything if I am still in view. I have another who loves all the new people at the vet a little too much, but will obey my commands and ignore a stranger's, making it easier for everyone involved if I'm present to tell him what to do.
I don't mind if they want to take them back. I mind A LOT when I try to gently explain why it's in everyone's best interest, foremost my dogs', if they either allow me in the back with them or do everything in the exam room but am brushed off or ignored. That doesn't fly with me. I now try to speak directly with the vet before the appt if at all possible if it's a new vet. Regardless, I don't tolerate a vet tech or receptionist telling me what they will or won't do with my dogs. I'm calm and polite of course, but they are my dogs, either listen to me or I'll find someone who will.
It unfortunately took multiple bad experiences for me to get to this point, definitely do not feel bad that your pup had one bad experience. Good on you for sticking up for her!