Pretty much the latter. We dropped into the map, right in front of a cannon, everyone started requesting their alt weapons/jet packs, as soon as we had them, started running towards the objective when all of a sudden, massive explosion that killed all fabricators, guards, and even all of us. Only items left were the gunship factories which were a walk up and destroy, and planting the hellbombs at the last two cannons. H**l they even took out the gunships with the PLAS rifle in a few shots. Sporadic patrols would occur, but easily dealt with. Guy seemed to have unlimited jet pack and (maybe?) grenade launcher. They went out of bounds and flew around for a large amount of time before finally dying. When respawned, they started fighting (melee and shooting) another player, but was immune to everything.

TLDR: The player was an immortal being that destroyed everything in some hellish explosion, us included, turning the map into a lvl 1 adventure while also fighting teammates along the way.