but ain't MC also said that he planned to fight from start? I guess it's like usual encounter with boss from previous chapter where running away isn't an option anymore. iirc, he planned to only grinding some stuff and bail out after a while but because bandit event stall them long enough to get jumped by dungeon boss.I think the implication is that rather than a useless 1 minute head start to fleeing he can buy them a much more reasonable 5 minute head start. given their agility based classes, 5 minutes of running can probably get them the fuck out of there.
he's most likely meant "It's do or die, Imma buy your guys some time so do your stuff"