If Guard 2 didn’t mean it when he said sorry that counts as a lie right?

I like the referenced riddle because you can’t “fully” solve it, in the sense that you know all the information. You can figure out which path to take (which solves the riddle) but you cannot simultaneously know who lies and who tells the truth, which gives the riddle a bit of an unresolved feel. (I’m assuming it’s one yes-no question only.)

This would be a pretty amusing encounter I think.

Mage: “Uggghh… well I translated the inscription on the door. We have to resolve their quarrel to dispell the magic lock.”

Bard: “So hey fellas, my party and I saw you from across the dungeon…”

“you ever fuck this guy’s wife?”