“The incident took place and nothing happens” always feels like a Protagonist special power: you’re the type of people who feel disturbances in the timestream, and so that that murder doesn’t happen feels important to you, even if nobody else notices it.

This is pretty supported in the fiction by that the Protagonist know before the game even starts what Incidents are in play. The Mastermind’s actions cause ripples in the timestream, and the Protagonists can see them coming days away.