So today I was doing some jolly invading in the royal woods, and I invaded this one guy and killed him. I appear back in front of Artorias' door, pull out the ol' red eye orb and invade some more. Wait about 20 seconds and then.. I'm being summoned? Dafuq.. I appear as a white phantom in the world of the guy that I'd just killed, in the same spot that I'd appear if I had invaded. I helped him and we killed the bastard, but I never put down a white sign and he never touched one for me.. has this ever happened to anyone else?
Yes. Well, no... you see my experience comes from the opposite perspective. I was waiting by the bonfire in Oolacile township looking for helpers. I selected a sign and summoned. A phantom did appear, but was not the one that I attempted to summon, and he spawned exactly where an invader would spawn. Thankfully he didn't leave, and we attempted to take the level, but it was so strange.. but I've also had the opposite happen. I summoned a phantom once, and he invaded me as a red on the very spot that I tried to summon him.