What exactly does he mean by "outside code"? Does he consider the entire Perl language "outside code"? Outside code (to me) means a chunk of code written by someone *not* in your shop. At a stretch, modules from the CPAN could be considered "outside code". readdir is not "outside code" it's part of the Perl language.

To be perfectly honest, I've never heard anything more ridiculous in my life and I'd be a little scared if this bloke was my boss.