I have complained elsewhere about the loss of the “might have” form in English, which is now rare even in printed periodicals. Here, from an article about an FBI agent who tried to warn about one of the 9/11 hijackers, is the first instance I have seen of the older and newer forms in hand-to-hand combat:
Through hearings this week and some in the future, Hill is painting a picture of missed opportunities. Individually, none may have prevented the attacks. But collectively, they might have unraveled the plot.