Of course he couldn't guarantee it; but he did say "almost", so I cut him that slack. :-)
Anyway, I think it's fair to say his guess was spot on. The site is not written entirely in Perl. There is a non-negligible about of SQL; and of course all the markup being flung around.
But I do wonder: When he says that wasn't what he expected to hear, what was he expecting to hear? That it is written in 10% Perl, and 80% Java? Or what?
I reckon we are the only monastery ever to have a dungeon stuffed with 16,000 zombies.