Jin's been kind of distracted in the thrall of his echo, pulling his gun with difficulty and trying to catch up with the snake as it harasses other people. The woman with the gun-arms is yelling and - oh, that must be Chris, well all right then.

Of course, it's not a huge surprise in the mess that's going on that Nick doesn't notice that the chair that's meant for him hits Jin in the face. It's not entirely surprising that Jin's unable to dodge it, being as he hasn't gotten any real martial skills back and just is a middle-aged (albeit genius) dad with a laser gun.

And when he falls back, knocking the chair a little closer to Nick and really trying to roll, he lands hard on his knee and hears it crack. "Ah--" Screaming about it's not going to make it any better but he definitely whimpers. His medical degree is telling him right now that he's probably cracked an orbital bone and that there's definitely something wrong with his kneecap.

He rolls, groaning, back towards a corner, over some ruined furniture, hoping to god the snake decides to more or less ignore him from here on out, though he's still got the laser gun in hand and is still shakily pointing it towards the snake. He hasn't even shot it yet! It's pretty galling that he's getting taken down by a chair of all things.