Players occasionally write in about The Killer from time to time but none, sadly, have provided explicit evidence of this actually happening without question.
I err on the side of players as much as I can, but when I bring this character into battle and see that he is correctly applying Perfect Disable with visible negative effect icons on his unfortunate enemies, it's tough to escalate the issue any further without an angle of attack.
Considering other angles, a possibility that I can imagine happening is that - as a result of various passive effects firing off in succession at the start of battle, highlighted in my previous post - there might be situations where the Killer successfully applies Perfect Disable before another effect removes it. To the player, there is no Perfect Disable to account for once all the effects are finished processing. However, because the passive was at one point disabled, some elements of it (depending on how it was designed) might not resume until that character's next turn - hence the "invisible passive disable" effect.
While some ability descriptions have been getting longer in recent days (apologizes, small phone users), we've been working on better describing when certain effects trigger within passives so you can better anticipate when they will proc again. Most of the time, it's at the start of the user's turn so long as that their passive is no longer disabled. This is why you've also been seeing an increasing number of "until they die" effects to help make certain effects stick. If you ever see a character whose passive is not disabled, yet they are failing to block or stop certain effects, it's generally because it wont fire off again until their next turn.
We'll continue to polish elements these elements of communication as much as possible without causing too much bloat in regards to skill descriptions. Hopefully this information helps plan how you approach certain fights.