earlier today, i wiped very early on at the last boss of hammer station. i started to run back, expected the group to wipe before i got back. they were doing well and did not totally wipe, i got to the bridge that phases in and out and they were struggling. by the time i got across the bridge, one DPS was left and the boss was almost dead. we pulled it out and we beat the boss, i was the last one standing. there was loot... long story short, from my limited experience, releasing and rejoining a battle does not seem to have any effect on loot..