Double spin kick and incapacitation

The follow-up kick didn't go through when my opponent was incapacitated by the first. Didn't know if this was a bug or really, really rotten RNG luck. The help file seems to indicate this could happen, but I've never seen it before. civilized <> You dodge DudeMan's slash. You parry DudeMan's punch. You parry DudeMan's slash. Your punch EVISCERATES DudeMan! Your punch mauls DudeMan. DudeMan absorbs the force of your punch with a studded leather girth. DudeMan is convulsing on the ground. civilized <> Quickly spinning on your heel, you deliver a crushing kick against DudeMan! Your double spin kick DISMEMBERS DudeMan! DudeMan is incapacitated and will slowly die, if not aided. DudeMan is convulsing on the ground. civilized <> Your punch misses DudeMan. Your punch EVISCERATES DudeMan! DudeMan is DEAD!! You land the killing blow against DudeMan.