All bosses active at the same time in Abomination Map

I killed Doedre and Maligaro and was working on Shavronne when I died a couple times. One of my deaths, the Nightmare spawned (with Shavronne still alive) as did the mini bosses that I already killed. Map did have "Maven intereferes" and there may have been a "duplicate" when this bug happened but I'm not sure.