Laser Feeling: It looks like something related to the parasites makes the hosts much more resistant to the stun. It's still possible to stun them, as he did show a reaction when Lorq hit him, but the infected seem to recover much faster and even be able to shake off a hit or two at max setting. For your edited question: It's not impossible but knocking him out like that is going to be very difficult. If you had a heavy pipe or something, that would helpOOC:
Usually, you would be able to change your action after an LF but since you were only defending yourself against an attack, I'll say that doesn't apply here.
The pirate manages to grab a hold of Zephyr and takes cover from Alex, Meyers and Lorq behind him. He digs his nails deep into Zephyr's skin, drawing blood around his neck. He uses the other hand to get a firmer grip on him. With one hand dug into his neck and the other arm holding Zephyr firmly in place, it's going to be almost impossible for him to free himself.
The others are seeing this from a few meters distance. He is holding Zephyr as a human shield, so it's going to be very difficult for you to hit him without hitting Zephyr.