Killed a “Convincing Infiltrator” on Rank and it resurrected even without reborn. I have a record of it in Arcane Tracker. I was ahead then until that bug occured which resulted a lose. I love this game. Hope you guys fix it.
And then you decided to keep it all for yourself, and not include a link when reporting the bug?
There are several ways to give a minion “Deathrattle: resummon this minion”, or to give Reborn to a minion.
Presumably your opponent used one of these and you didn’t notice.