This can strike during any televised sporting event. Essentially, a commentator draws attention to a particular aspect of a game or a player, or makes a prediction based on past performance, and is immediately proven wrong by events. (Everything2.Com)
selection bias in action. A commentator makes so many comments about the game and players that over the course of hours of constant speech, there are bound to be several times they are immediately proven wrong. These stand out in memory.
Yes, but seanahan's still right. Commentators say lots of things in the course of a game, and immediately after every thing a commentator says, something happens. The few times these things are directly counterposed, we notice them.
Which doesn't mean it's not a phenomenon worth describing.