I think the play clock in the NFL when ot runs down to 0, it's a situation like NBA that its 0.9 secs., .8, .7,.6, etc. Like the official responsible is to count 1 extra Mississippi when it drops to 0. Course the NFL has that other issue where clock shows 3-5 secs and a QB or official does the 1 hand lift it up pump and resets the clock to 25. As if that playclock started early countdown and wind it back.