why the hell would he just walk away... why not try and write on the ground or gesture to ask shit from them... fucking MC must have brain damage to more than just his linguistics.
Language barrier and tabi-like mentality, whatever problem they had wasn't his problem, he just solved one of it for them actually, so bro just took the reward "voluntarily", while he can't speak, he could write but they'd most likely don't know what language it is.
And beside there's really no point in doing anything beside looking at boobies afterward imo, if he were to try anything now it's more likely to stir them up thinking he's hostile and attack him instead, so I think it's chill.