As a professional trainer, I hesitate to post on this thread, but what the heck. Years ago when I was just getting started, I used a pro for a short period of time. I didn't do my homework and had a bad experience. He talked a good game and even had some videos out, so I thought he was the genuine article. A short time later, I realized what he was and brought my dog home. Since then, I've seen him at tests and even judged him a couple of times and it's embarrassing to think that I sent a dog to that guy. But if I had really done my homework, that never would have happened. My point is that the client has the responsibility to perform due diligence before turning his dog over to a pro.
As a professional trainer myself, I would never tell a potential client anything negative about this guy (or any other pro), but if they asked me about using him, I would probably suggest some other pro in the same part of the country and let them decide for themselves. I would also give them some ideas about how to properly vet a pro before sending them a dog.
On a separate note, the issue of abusive training can be very complex because different people have different ideas of abuse. Newbies especially have a difficult time understanding some of the methods that we use. I take the approach that a client is ALWAYS welcome to watch me train my whole truck of dogs. If they have questions about my methods, I will do my best to explain them. I also try to train as if the client is always looking over my shoulder. If I wouldn't do it in front of the client, I wouldn't do it when the client isn't there.
But if a novice sees a pro FF a dog and the dog vocalizes, or if he sees a pro use a collar or a stick in a perfectly acceptable manner, he may construe it as abuse and tell others that a trainer is abusive or heavy-handed. That's not necessarily a good thing.
I agree that the bad pros will out themselves. The problem is that there are new folks entering the sport every day, so a slick talker can always keep a few dogs in the pens.
Now before the pro trainer police try to out me, I'm on RTF during the middle of the day because Monday is my day off. No clients are getting screwed while I fool around on the internet.

And yes, pro trainers do get days off from time to time.