[Kalimac]

Can't see Gollum hanging out with the Orcs in Moria, especially after what happened to him in Mordor (and the fact the Orcs who have been living in empty mines for a long time are not likely to be too picky about potential food). He probably slunk out some other way that was impassable to the Fellowship - probably hid in a corner until the fight was over, then found a chink somewhere and slithered out and followed them to Lorien. He might have raced ahead of them and gotten across the bridge before they ever arrived there, but that just doesn't seem like his style to put himself in front instead of behind...