One of my teacher in highschool did this to us once.
They are contractually terrible guardians. Leaving the children unsupervised is part of their quota!
Had this at university. The lecture (where half the people didn't actually come) was held in a large auditorium. The exam was held in a smaller room, where we HAD to sit shoulder-to-shoulder making NOT looking at the neighbors sheet actually hard. The professor then sat down, feet on the table, unfolding a large newspaper in front of him. I didn't cheat anyway, but if I had known in advance, even I might have been tempted to skip learning properly ^^'
Another case was the sailing course on the school sports-week, where the trainer left the room for a smoke XD
In ths case though... Sure, its "if you didn't pay attention, you're risking your own life". But anyone not properly knowing the plan is ALSO risking THE PLAN, so...
Eh, if they cheat, it means at least one of them knows what's going on.
a-See "what comes next?" above. "Cheating" by us is unimportant, even encouraged. So what the kids do may be of no importance and they really don't care, or...
b-they are being tested to see if they will cheat [or other behavior] and in fact are being closely watched, possibly by our wino friend. Our perfect, all-knowing ruler may have said these magic-users are to be trusted and used, but they were horrid criminals not so long ago, and so it is not really violating orders to keep a close eye on them and give them a "chance" to show any criminal tendencies they may still have.
In college, not long ago, i was taking the final exam of the subject i hated most. The professor didn't give a damn about life in general and prroved it by leaving for almost ten minutes when i was about to speak of the last point. Gave me enough time to cheat the hell out of it