[spidey]

I think your vet might have misled you a bit and/or he doesn't understand why the emerg. clinic has you sign a waiver (which seems unlikely). It's standard procedure that if the client does not wish to have a treatment done which will fix the problem, that they have you sign a waiver in which you agree that they explained things to you and you will not hold them responsible if something goes wrong (it's no different from people checking themselves out of hospital against medical advice). Emergency clinics are expensive because they are often the only game in town at that hour, so they can be, and because you pay a premium for service outside normal hours (the same reason that food from the convenience store is normally more expensive than food from the grocery store).

It doesn't sound to me like the emerg did anything out of the ordinary.