And how do you actually show the interviewee failed to do any of those things?
I think the whole idea is idiotic, but this particular point doesn't seem like it would be the blocker. We already have employment contracts which state hours to be worked and similar mundane details, this wouldn't be any different. Such contract details would only be tested if someone tried to exploit a loophole, like showing up for a bunch of interviews to get money but with no intention of actually completing the tasks.