Hii currently im expierncing a bugged wherein you could see the enemy or yourself at 0 life but you aren't at 0 life yet, please quick fix this bug , as of today im not the only one expierncing it , also if your at 0 life you can still put card , parts of my strategy were broken due to this game breaking bug.
I believe the Bug you are talking about occurs when the Ability: -X Life is at play.
This can also happen with Pillz. It is an issue with the App I believe.
I will post it that this forum if I were you.
Bugs/Issues: Bugs reports
Its happened to me today too - i also played a match where an ector took off to more life points than usual, leaving me with 2 life instead of 4, while his min is 3