One of my characters arrived just after the Queen of the Reef had been killed, so I left the character just outside the cove to login another character. When I logged in the first character again, I joined the fight that already was in progress. I could move the character normally and activate other players' synergies, but the character was not able to attack with weapons or skills by mouse clicks and number keys. The character did get credit for completing the quest when the Queen was dead. I didn't try reloadUI, as I thought the character might not reload in time to complete the quest.