Erm, how do you know they're targeting an invisible ??? in the first place?

That aside, what I do is put a macro "/item "Pop item" <stnpc> and then activate it before the ??? is even up. I spam tab 'til I see ??? and immediately hit enter. Sometimes I'm lucky and I grab it just as it appears, other times, I'm a second late or may even get beaten to the punch. It's possible it's just a fast macro, not necessarily botting.