Lieam does not participate in the conflict.
There’s really no way for a character to wander into a conflict in progress. Either he’s in the scene or he’s not.
If he’s in the scene, he participates a team member. If, in the narrative, Lieam’s rushing in to help, then just give him the third action for the exchange.
If he’s not in the scene, then Lieam’s player is, of course, a good player and sits and cheers his friends on while they have the spotlight.
-L