I think people need to realize here, it's not just about the kid gettin chewed out in practice. It's more than that. His belief is about coaches (and in this case Kill specifically) are basically manipulating kids with their power. Not saying he's on point or whatever, but I guarantee you there are a boatload of athletes who wholeheartedly agree with him, and I'm sure plenty of others who agree this occurs, but just don't see it as an issue. But then of players who would agree, I'm guessing most of them aren't leading receivers on their teams and, as he said, basically free to do what he wants cause he isn't on scholarship. We all know there are kids on the team right now, who may not say a word of agreement with Barker, but feel the exact same way. That's fair for them to feel that way.
The problem is, I'm pretty sure Kill has done nothing differently than a vast majority of coaches. But, his problem is he did a "power play", so to speak, with a star receiver who basically admitted he's had past issues with authority figures, and was also in position to not take it (no scholly removes some risk for him) if he didn't want to. When I'm watching this Kare 11 interview, he doesn't really lay out an environment where I think Kill is out of line here. It really comes off as "I didn't like the way I was coached, so I left". To me, that's not fair to Kill then, to paint him as this evil master manipulator like he's doing something out of control.
Kill is human, (contrary to how some on this site paint him lol), he'll fly off the handle, he'll mess up (probably a whole lot), so he probably did go overboard with the injury thing. But I think the proper way to address this is rather than pop off a 4,000 word rambling rant, just simply and calmly acknowledge that Kill did some things he didn't appreciate and thought were out of line, and that because of your scholarship situation and the freedom it allowed you, you decided to transfer to get out of the situation. It comes off reasonable, still puts a little spotlight on Kill's methods, while also allowing you to not come off as someone who may have some issues internally.