the same way every legal rule is enforced / checked: people look and if it seems iffy they examine/complain, and if a problem is found people get fined/jail.
"7.5 hours - reviewing output"
Sure, if they actually spent 7.5 hours, and it was a reasonable amount of time. If not, perhaps it would be seen as evidence of incompetence.
In the real world, lawyers submit detailed bills and their clients examine them. If you don’t, that’s on you.