If I have a button that lets me be invincible, and use it at the right time - is that 'outsmarting' your opponent who doesn't know you have this button? No. That's not how outsmarting works. That's the player using his ability 'well' (pressing a button hardly counts as well, but whatever) - but it hasn't been conveyed to the other player, there is significant information asymmetry.
It's pretty much the same issue as armour lock, nerfed a bit.
If I have a one hit kill weapon and the other player has no idea I see it resulting in the same kind of situation.