I would ream the groomer up and down the place if that happened to my dog. I've worked in a grooming facility before, and there is NO EXCUSE for letting a dog die like that! Our cage dryers had timers, and even with ones without timers, if you PAY ATTENTION there shouldn't be a problem. We never had any dogs get hurt by the cage dryers.
The boss there used to get this grooming magazine, and I read an article in it once about this place where a cage dryer malfunctioned and caught a dog on fire! The dog of course died a painful death, and the owners, hurt and outraged, stood outside the business telling everyone how they killed their dog. The business was of course, ruined. The owner blamed the incident on faulty equipment, and the cage dryer manufacturer blamed it on the business owner, stating that the dryer wasn't cleaned out properly. I don't think anything was ever proven either way.