Just my 2 cents, but yeah, if it were my dog I'd find a new trainer, (a) because I would not allow a vet to forcibly roll my dog on its side, and I sure as **** wouldn't allow a trainer to either! And (b) because you cannot correct a dog into being confident!
My dog is and always has been pretty rock solid environmentally, fireworks, gunfire, cars and semi trucks, pans dropping on the floor, elevators, trains, steel grates, none of it bothered her a bit. But she had no reason to go into the basement at home ever, and consequently developed a kind of phobia of all things subterranean. I first noticed it when she started giving subterranean store entrances a wide birth, and verified it at home by trying to get her to follow me into the basement. Totally irrational fear, and really my own fault for not ever taking her down there as a puppy - it just didn't cross my mind!
I got her over it by leashing her up and taking her down there, but such a direct approach may not work well for all dogs. Once in the basement I just let her explore, then did some light obedience work. After a few trips down like that, she was fine going down on her own. But it depends on the dog as far as how fast you can go. Watch the response, if your dog is cringing and shaking I'd definitely take it a bit slower! It's really about trust. If your dog trusts you, and you honor that trust by not overwhelming him, you can incrementally help him get over these fears. If he's pushed beyond his threshold frequently, he won't trust you enough to make progress.
I personally don't like using treats for things like this, because IME 95% of the time people don't do it long enough to really accomplish classical conditioning which takes a long time and many many many repititions. I prefer to reward them for obedience around the distraction of the scary thing, and then incrementally move closer.
Just saw your latest post, so I'm updating to add: absolutely change things up as you're working with him. Dogs are incredibly good at patterns. Breaking it up and changing his routine is a key element in teaching him to focus on you and pay attention! Good luck, but I think you got this! You care enough to notice and to ask and question things!
It's not the size of the dog in the fight, it's the size of the fight in the dog. Mark Twain
Last edited by tim_s_adams; 04-21-2019 at 12:38 AM.