Updating.
Because of my Yelp documentation of what happened with my dog during her final moments of life, this organization contacted me.
Without going into a lot of detail, the individual on the other end of the line who called me, a veterinarian, described the events of my dog's death as something that might happen when given the dosage to euthanize the dog. Doesn't happen frequently, I was told, totally not something you want to see (definitely not something I wanted to see). The question still lingers in my mind: why did the vet state that she better give her more of the substance after the dog did what it did when she was supposedly dead? It was an apparent admission that the dog had not been given enough of the liquid to completely put her out.
Whatever the case, I will be visiting my regular vet in the near future and will be asking him his opinion on this situation. If he correlates the other vet's statements, then I will post that here as well, to be fair about it.