I've known Jonny since he was a junior in high school. He does have some clashes with coaches and, to a lesser degree, some teammates. Rather than write a book here about each instance, I can tell you that every time, that I am aware, it had to do with a lack of effort. He never got on players for mistakes, but rather being lazy (whether it be off-season, practice, or during games). He's intense and wants to win. In my opinion, he'd do well mentoring a hard-working core of young guys that aren't afraid to bust their asses.
Coaches are not immune to this either. I know of two instances when he demanded more of the coaches (time put in to 'coach up' younger guys, specifically) and didn't hold back his feelings. Never done publicly, but let them have it for being 'lazy.'
He's intense, no doubt. But at least it's about winning.