I would have maybe won a battle against Pimpnubz if they do pierce lowered attack stats. BUT I don't know if they do, nor does anyone I believe and that's why I threw this question out there :D
If the attacker is using a Physical move, and is at +2 Attack while the defender is at +1 Defense, then a critical hit will ignore the Defense boost but not the Attack boost.
>The same occurs if the attacker is at -1 Attack and the defender at -2 Defense, with the Attack drop being ignored but not the Defense drop.
Basically, the quote sums up this: (Special) Attack Drops are ignored. (Special) Attack Boosts aren't ignored. (Special) Defense Drops aren't ignored. (Special) Defense Boosts are ignored.
Source
Defense Drops are calculated in Critical Hit calculation. Albeit, Defense Boosts aren't.
Hope I helped. :) Source, Source and Source