AOL collector unstoppable bugged?

It says in his abilities that he gains unstoppable when he loses 1% of his max hearth, but he seems to get the unstoppable nearly every combo I do, when I’m absolutely not dealing that much damage. Am I missing something here?
1
Comments
When abyss havok is bugged in favour of the player they fix it, but when the collector is bugged and screws the player over they don’t?
Seems fair lol.