I think the devs taught the wrong life lesson here.
Your example doesn't fit in this case.
First of all, the thing I am talking about is "bigger" that what Wintersturm or whoever has to learn. And even if he had gotten his item back, the moment he realized that he regrets the deal is the moment where he learned the lesson.
Your example would fit if it was not the (marginally) older brother, which more or less represents someone "equal", but perhaps his babysitter (and what are admins else than babysitters
).
What would you do if you heared that the babysitter you allowed to take your boy to the mall to spend the money you gave him talked the child into buying her some make-up or condoms or high heels or whatever bitches need?
Sure, concerning your son nothing would change. He has to learn that he mustn't allow other people to talk him into spending his money for them. But how about the babysitter? I mean: she didn't neglect him, let him alone, let him play with siccors or something like that. The job of a babysitter is to look after children, and that's what she did. But would you hire her another time if you got to know about this? Or wouldn't you say that the babysitter exploited the child she actually had to protect? Never mind if the child gave the money deliberately or not?