There's a few things here:
1. It was an obvious catch and fumble. This was the worst non-overturn by replay I've ever seen, and I can't even remember something close. Usually, there's at least some shade of gray - ball with a slight bobble, only 1 1/2 steps, something that could lead to an inexplicable non-overturn - but on this play there was nothing. At this point, I was wondering what the grounds were for playing a game under protest. Not that I would've even advocated doing so, but I was so exasperated because...
2. This came only a few plays after the "fumble" by Cobb that also should've been overturned. Now here, I wasn't quite as irate as even though the stadium replay showed the ball coming out because A. it was in the middle of players with mostly bad camera angles B. it's possible the ball was wiggling slightly before Cobb's elbow hit the turf (couldn't really see it or not on the board).
3. What's with the 3 illegal formation penalties on XPs (2 on us, 1 on Purdue)? This is like the 3 illegal linemen downfield calls last week. Illegal formation is something you could pretty much call on just about every XP/FG if you wanted to. Moreover, the XP is a near-automatic play. Re-running it just allows for injuries. Stupid, stupid, point of emphasis if that's what it was. Yes, yes, we should've made the XP from 5 yards back, but seriously, we shouldn't have had to.
4. The "fumble" by Leidner that did get overturned on replay was ludicrous. Leidner almost had 2 knees down the ball came out so late. Thankfully the booth got this one right, but it shouldn't have gone that far.
This was the worst reffed game I can remember. They pay these guys but they weren't even watching close enough on at least 3 key plays to correctly identify a fumble or not, and then the ridiculous emphasis on formation on XPs. What a joke. Thank goodness we won or I'd really be pissed.