If I had to distill the training - there are dominance elements, but CALM and firm is the vibe, and giving them opportunities to be good. He has us sort of bark at the dog as a general “look at me” then pet them for paying attention, and a high pitched gentle “free” or “whee” to release them. Maintain a 2 foot bubble when eating or working from home, don’t let them cuddle up to me. I always made them wait until I walk through a door but he said make them wait until specifically released. So there is some dominance based discipline in there and it does help, but never violence, never use hands to correct them only voice or leash. Nothing that makes them afraid of you will make them respect you.
It was expensive as heck because we have 2 dogs but lifetime support and I can see it’s working. We didn’t have a free for all before the training either - always had standards of behavior for them, heel when walking, etc. We are trying to get to the point they can be walked together and not freak out even if another dog on a leash barks at them. It’s a long road but improving all the time.
I guess one good thing about being injured is plenty of time with the dog to work it out. And yes behavior problems after a traumatic event are normal as heck. Stay consistent, and manage the environment as much as you can at first, don’t give an opening to misbehave, reward with attention when they do what you want.
ETA: it really does depend on the dog. My daughter’s dog is just not emotional, he may ignore what you tell him to do but doesn’t freak out, like, ever. A little kid wanted to pet him at the park and literally screamed in his face and he just sat there, it didn’t phase him. So she can be quite rough with him and he is fine with it. Just “oh, THAT’S what you want, OK.”