It would seem so.
Yesterday whilst enjoying what started as a smooth run through the Tomb of the Vulture Lord, we got invaded 3 times in a row. Each invasion pretty much within seconds of the previous one ending. This would normally be fine, we'd get a scrap and some entertainment out of it, however the annoying thing was each time there was nobody actually invading the dungeon... Every invasion we searched the entire dungeon, but found nobody. Which meant because the timer insists on running for the entire 30mins each invasion (despite there being nobody in there), we had an hour and half wasted...
Then near the end of the third invasion our Sorcerer disconnected and when he logged back in he was inbetween the door outside the instance and the portal. Where he found an AFK Runepriest... Coincidence?
Perhaps, but I wonder was this guy invading our instance solo, then immediately leaving and sitting AFK waiting and hoping we wipe on a boss? Coming back after 30 minutes to repeat it over and over? Would the game mail the loot if we had wiped with him outside the instance? I don't know, but it was certainly strange to be invaded like clockwork 3 times in a row, by nobody... Something wasn't right whatever.