1) My weapontrip skill is perfected and I got the echo “Your weapontrip seems to slide around Someone.” 3 consecutive rounds in a fight (instead of the usual “Your weapontrip misses.”) without being able to trip my opponent. Does this echo (first time I see it) indicates that it's not possible to weapontrip this person? If so, how can you immune yourself to weapontrip???

2) Is it possible (from hidden) to poison knock-out someone while he's in a fight with another opponent? If I remember correctly, it is possible to blackjack someone in a fight.