A lot of things can go wrong in follow through and coming back to the target, but getting the first shot off fast and accurately is a skill that can be worked on with dry fire and low-recoil rounds. It's also a way to prove to someone they have an anticipatory flinch and the reason they're missing isn't managing recoil - help them separate the two different issues.
Some things like trigger reset you have to actually feel, so shooting a lot of something cheaper means you get more cycles on the trigger. 22LR ARs and finally getting a factory 22LR Glock have been good teaching tools.
Making wind calls for someone else to shoot is also very instructive. You can do it in groups, have everyone write down their call and compare to the spotter's call and actual impact. Everyone wants to shoot, but wind skills are so much more critical than anything to do with the technical side of building and loading for a rifle.
Misleading him about it was messed up, I agree that's how you make kids never want to do it again. But I will say that there was something to my old man's theory of being up front that it was going to hurt but I'd live through it, and then working on how to learn to handle it. I laugh about the halo scar that all 30-06 guys have, but I earned mine after I knew better and deserved it.
I've also heard the stories of old guys tying string to the trigger of a CMP M-1 and running through a en bloc clip with the only goal being stay on target, get back on target, focus on the target and ignore the recoil.