"Setting up your usually consistent kicker for relatively easy kicks isn't exactly conservative in that situation. It is conventional"
And that's exactly what Michigan did NOT do in the last drive of regulation. They needed to get Gibbons closer to put the game away; they decided to milk the clock instead. They got lucky on two straight 3rd-and-longs and then opted to run-run-run and went BACKWARDS, then opting to punt. Then the defense went away from what was working and allowed PSU to cross the field in 30 seconds.
The one time they could've used Gibbons conventionally, they declined to do so. From that point they were FORCED to be aggressive in OT because they HAD to score.