According to RAW for swarms,
A swarm can enter or move through an enemy’s space; this movement does not provoke opportunity actions.
I assume "pass through" in this case means "move into and out of as part of the same move action".
So if a swarm wants to move from one square adjacent to a Medium PC to another square adjacent to that same PC, all it has to do is pass through the PC's square first, right? And there are no consequences to doing so, unless someone else has an immediate interrupt they can use, or there's a status effect "can't/must move closer/farther". If not, the requirement to "pass through an enemy's square" can be ignored.
But, a swarm is subject to OAs normally when moving away (fleeing) from adjacent to a PC -- as long as it's not fleeing through another PC's square. Right?
Let me restate this. I have a question about interpreting this rule. There seems to be some ambiguity -- the rules don't say it clearly -- but the way I'm parsing them, when they say "moving into or through a PC's square does not provoke OAs" this immunity is not limited to OAs by the PC in question -- it's immune to all PCs' OAs. Period.
Am I right in my interpretation? Or has this been superseded by some errata?
For reference:
http://community.wizards.com/go/thread/view/75882/19676262/Swarm_question?post_id=334723610