While it's true that, within the logic of this game, you should not be able to talk to a spore servant, there are still a few exceptions. Most of these are cases where an NPC has a proximity dialogue which would have triggered if they had survived. You don't have to click on Barcus Wroot, after you save him, for him to talk to you. Likewise a dialogue starts automatically when he is raised as a spore servant. Ellyka has one if she gets killed by the Gith patrol. Mirkon has one killed by the Harpies, and gets raised twice. Under some conditions, Nere and Gekh Coal ask for a bribe when you raise them, or they attack you. Halsin has one if you raise him after betraying the Grove.
Also, if companions are made into spore servants, you can talk to them, though attempting to invite or dismiss them from the party breaks things severely.
Yeah ... Swen is obviously quite benevolent Dungeon Master who is not following rules by the letter, as long as people have fun.
