As has been noted in other posts, it can be difficult to tell when this skill has been triggered for an opponent. By way of two examples:
You are fighting against Phoenix. You slash her health down bit by bit. A healer starts healing her. You manage to take her down to ‘zero’ though. Her HP remains frozen at 1 and a shield appears. You blast the shield down. As the shield disappears, she dies.
You are fighting against Gammond. You slash his health down. A healer starts healing. You take him down to what looks like zero. You can’t tell though because it shows up as 3k,6k,10k… You keep shooting. Did he go down to zero or was it just 1k? You keep shooting at him until he’s dead, not knowing if he died because of all the lead you pumped into him right at the end or if his death had actually been triggered 10 seconds ago. You sigh and open up your browser and head to the forums.