It could also be coming in from other mmos. In WoW for example some aoe's will flat out one-shot any single character, but the damage is designed to be spread around. However, some aoes will almost one shot a group of people which means if they are not already healthy they're dead. If they both occur in the same fight (not uncommon) I could have trouble remembering which was which.

Also cannot account for pinball avatars (also me) where I coincidentally end up running towards the same open space someone else was aiming for.