After the game, Hans said that Gary Anderson punched him in the back and when Hans turned around Gary had a HUGE grin on his face - celebrating the win. Happy to have beaten Utah.
I don't think any of the ex-Utah guys who are at BYU are all that conflicted, to be honest. I think they are exactly what Kalani describes - they love Utah and Utah's coaches - those dudes are their friends. But that doesn't mean they don't want to beat them every single time. Remember - Gary has a close relationship with BYU's players now - so he is invested in them doing well and being successful. I'd be shocked if he didn't want them to win.
So my answer is that Gary Anderson wasn't conflicted - he wanted BYU to win. I suppose he may have been somewhat professional too, in that he didn't freak out per se. But I believe Hans - that he was happy and grinning after the field goal and was happy for the win.
For the record - if you think Hans made up the story - it was on the post game while he and Wrubell were talking, and Wrubell was chuckling with Hans about it. He was there in the booth with Hans when it happened and saw it.