Even if he were trying to keep his balance, it wouldn't matter - the rules don't care why you're flapping your arms, only that you're flapping your arms. It's still holding, for example, even if you didn't mean to hold.
@GophersInIowa That's exactly why the rule is in place - even a moment's hesitation can give the returner an unfair advantage, and waving the arms does exactly that.
The rule is you can't wave your arms at all, your hand doesn't have to go over your head. You do have the right to alert your teammates to get out of the way - but if you do that, you can't return the ball. That's the rules.
And even if he was a real estate agent, it's not very credible that he would have a conflict of interest. Officials have day jobs. Most people wouldn't even know that their real estate agent was a college football referee - unless angry fans targeted and doxxed him, which isn't on him.
There are still a lot of Iowa fans who don't understand the rule, won't listen to the rule, somehow think that if they don't like the rule it somehow doesn't count, insist it's not reviewable when it clearly is, etc.
Iowa fans are saying "If it was an invalid fair catch, why wasn't Minnesota penalized for trying to tackle?" But if you attempt to illegally move the ball, you're fair game. You can't expect the defense to stop when the offense isn't stopping.
On the radio, they said it wasn't an illegal fair catch signal, but an invalid catch signal. The former is a penalty, but the latter is just a dead ball. I don't know the details of the rule.