Rumor, as I understand it, is that he's been studying with him routinely. If that's true then the answer to your question is both.

I have no idea if any of this is true. It seems like there could be at least three options, he was upset with BYU for some reason and intentionally sabotaged things, he wasn't thinking and didn't realize that his friend would sabotage BYU, or he got crosswise with someone else on the team who has made up these rumors for some reason.

So I'm not saying what I think happened, in just saying the rumors make enough sense to be true. Meaning, I think it could have gone down any of the 3 ways above. Whatever it really was we may never know for sure, but it's at least believable/plausible.