All that said, I was just looking at OLD v1.2., and based on this feedback that ability has now changed. Here's a preview:

Acid Blood. Ogres have acidic blood. In addition to gaining an additional 5 SOAK (acid), melee attackers which cause more than 10 slashing or piercing damage in a single blow take 1d6 acid damage from the blood splash. This acid damage seeps through armor, which does not SOAK it, although it is SOAKed by natural or magical SOAK.