Just don't chastise him for experimenting with the language and reporting his findings. He's learning. Let him learn.
Oh, goodie. Now that's helpful! Anyone who's experimenting with the language, we just let them go, and admire them from a distance, keeping silent.
And then we wonder why people stop programming in Perl because their production code failed in mysterious ways. They walked into a swamp, and we let them, cause that will "teach them".
Now please excuse me, I've some "dangerous curve" signs to remove.