If the details in Good Magazine are correct, then it looks like costly signaling, not cherry-picking.

The details are that he was condemned at the APSA meeting so harshly that he got a public apology five years later when his prediction turned out to be correct. If he were making tons of controversial predictions and getting publicly condemned every meeting, the Iran expert should have felt no need to apologize when he's right once. It's important for this story that APSA is all of political science, not just Iran.

But these details look hard to check. I'm inclined to throw them out and call it cherry-picking.