Yesterday the Dark Orb boss in veteran Depths of Malatar randomly reset the fight despite some group members still being alive. This happened us twice last night; the first time the tank was still alive and the second time 3 of four members were still alive. And I don’t think it should be any timer either since neither of the fights were running very long.
Adds were tanked in the middle and dd’s and healer were positioned in the middle ground between entrance and the middle area, so no reaching out of the area either or anything like that.
Also Tharyya at the king Narilmor randomly teleported couple of times to the next location instead of running (for example after being struck by the ice pillar), but that might be feature, not a bug.