I see a plus side to this story. Even though I don't think this was part of an officially sanctioned "training" program, learning how to control an emergency vehicle in the snow is an important bit of training that's usually only experienced by accident (pun intended).
That said, if this was a "Hey, it snowed, come down to the lot!" with the first line ambulance and an on-duty patrol car, and nothing from the volley captain or the police training officer, there may be a talking-to (or more) warranted, especially if it meant potentially destroying a first-line bus.
Coming from a NJ volley squad, I had NO emergency vehicle training (Hey kid, you got a driver's license? Okay, Vinnie's gonna let you drive back. I need you driving on Tuesday nights - anyone ever have similar "training?"). I didn't get it until I began working professionally in EMS in a program that put all its employees into an EVOC program. 25 years later, I went through the course again and had a blast. Now that one of my kids is driving, I wish I could get her this sort of training, instead of teaching her just how to drive in ideal conditions.