Forum:Samurais and traps

my friend had 2 six samurais on the field, with the effects of destroying a face down card and a face up trap card, one attacked, and i played mirror force, then my friend said he activated his monsters effect to destroy one face up trap card[the one i had just activated]. he cant do that, can he? i told him he couldn't but he insisted he could.is it possible for him to do it?