Just having fun there. But Captain Pike being Lieutenant by rank is fun indeed, especially as we learn he made (Fleet) Captain only later on...
I've always thought that Pike as a substantive lieutenant is a bit of a stretch but WNMHGB suggests that the single strip covers all junior officers (ensign to lieutenant commander) with two stripes worn by all senior officers (commanders and captains), so Pike was a LCDR, rather than CMDR (Kirk in WNMHGB?) or CAPT (Kirk from Man Trap onwards), it's still not great but it's an improvement.