i just said one should resign a 'completely lost position' rather than winning on time.
Why??? Why should he resign??? I guess a 'completely lost position' is something that you'd win with 100% certainty if given enough time. But you don't have enough time to checkmate, you don't even have enough time to force a draw. So why should your opponent resign if he can win within rules of chess? Why do you deserve to win if you can't checkmate within the rules?
Plus, the game IS over, so no use crying about it now.