So he's got new people . . . and he's trying to find exercises for them to do to help them learn . . . so he's asking people on Perlmonks about broken example code . . . so that these people he's trying to bring up to speed . . . can learn . . .
Wait, I think the Wookie just ran off with the pony there.
I could see the benefit in using intentionally broked code as a teaching tool; however if the teacher themselves doesn't understand why it's broked they're probably not the best candidate to be teaching people (at least not with their present level of knowledge; the optically unreceptive pathfinding the optically unreceptive as it were).
Addendum: I will grant that Increment avoids warning unexpectedly is somewhat wonky behavior, and whlle I can deduce why it behaves that way I certainly could see how it's surprising. However calling things like Data::Dumper converting characters to their backwhacked double quote equivalent when you explicitly tell it to do so or expecting to get data from closed filehandles "unexpected" behavior just makes me want to quote Inigo: "You keep using that word. I do not think it means what you think it means.