Maybe he had been planning to do his hard workout / Time trial this morning (thinking that the races were tomorrow). Then, after being kind of annoyed with all the hullabaloo going on, he figured if anyone was encroaching, it was the other 100 runners who were horning in on his workout?
Or
Maybe he wanted to show all the college coaches who overlooked him want they missed out on?
OR
Maybe someone bet him $10 that he wouldn't do it... easy money!
I wonder what, if anything, will come of it? Of course, it's super embarrassing for the UIL. I'm sure they are conflicted because they most certainly want to make him pay, but at the same time, I bet they would like as few of people know about this as possible.