People just use different terms for certain moves whether it be boxing or other sports. Emmanuel Steward said it early on, I think the 3rd or 4th round, that Mayweather was looking to land the check hook on Ricky. Floyd rocked Hatton with it in the 8th and dropped him 2 rounds later. With both Steward and Floyd saying that term that night, I figured that term is just used more in boxing gyms around Michigan. In the gyms, I had only heard “hook him and slide out”. Same idea.
I always thought they just mean a left hook thrown off the back foot as a counterpunch to a bull rush type fighter as far as a " check hook " goes. Ali vs Bonavena, De Jesus vs Duran and Mayweather vs Hatton are three examples I can think of off the top of my head. Cheers All.
Odd that you say it wasn't something pulled out of a Floyd fans ass, considering what Stewart died of