Doing the knights events on the overflow server, we killed the 3rd knight (green) with 0:02 seconds on the timer – The event flagged as success, and we got the loot, but the pool didn’t spawn to go to the breachmaker.
First time I saw this since the hotfix, so I’m guessing it being so close to the timer expire is what caused it, but either we were successful, and get both loot and the pool, or we failed, and we shouldn’t be getting anything.