Just as a blanket statement, I really like the idea of calling the SID and telling him you are going to have to call someone on a cell if he/she doesn't help out. And if you have to break the rules, letting them know first, in my experience, really helps. SIDs aren't dumb. They know some stories are different than others.
A backup spraining his ankle isn't worth a cell phone call. A starter getting busted for DUI is. SIDs know everyone is trying to break a story. So at least giving them a heads up instead of letting them be surprised by a story is the way to go. Maybe that didn't happen at UT.
As for this case with Hooker, I'd only say this: If you are going to break the rules -- and he did -- for a story, it better be worth it. It wasn't this time, in my opinion. If Inky says he's quitting football, that's worth it. If he said fans tell him to get better, then it isn't.