There is no excuse for clipping a dog when asked to strip, if the dog "went mad" why didn't the groomer either ring you immediately or tell you she wasn't able to complete it on this occasion and why, and offer a return visit so that the dog could get used to it/her, or simply give the dog some time out and then try again ?
I can't believe that a
professional groomer, taking money for their services didn't know how to handle a scared/stroppy Cairn

it isn't as if it's a huge dog to handle :rolleyes: some quiet time and patient handling would be the least you should expect ;)
In
my experience a dog is more amenable to hand stripping than clipping (which can be very scary if the dog hasn't
ever been near a clipper) if they are new to the groomer - providing the groomer
knows what they're doing ;)
As for growing it out, if the dog had a good harsh coat then in time it should return, but how long it will take can vary. If you are already stripping a Petit (PBGV ?) then I'm sure you'd be able to strip your Cairn to show standards ;) Go to some open shows, approach the Cairn people and they'll help, if your breeder is unavailable, or maybe your breeder/breed club could put you in touch with someone local who could help you? ;)