The status effects that provide a figure with the Bleed, Burn, Daze, Frost, Stun and Web tokens, and even Knockback even though that doesn't have a token usually say something along the lines off "If received attack inflicts at least 1 damage (before armor) place said token on the figure."
Now, we've assumed that the damage before armor part means that the figure receives these tokens (or the Knockback) even if it doesn't actually take any wounds due to it's armor, and in almost all cases it makes sense. I can imagine someone who gets an attack to be stunned or dazed or webbed or knocked back by it, however, in the case of Bleed it doesn't make any sense that a character suddenly starts bleeding after an attack that doesn't even actually hurt him.
I haven't played Descent a whole lot, on and off some casual games at a friend's place and part of the RtL campaign, but recently I've purchased my own copy with the expansions and am planning to run games more frequently with friends. So at the moment I'm inclined to rule an exception on Bleed, saying that you only get a bleed token if part of the damage actually passes through your armor, which seems more logical to me. Any thoughts on this by some of the more experienced players here?