Eunwoo moved quickly to get out of that nightclub. He was only there to have a good time and a little break. Unfortunately, he doesn't get such luxury as an famous celebrity, when someone in the club recognized him through his disguise. Which means paparazzi were on their way as well, so he took his escape towards the back exit of club. He was in such a rush, that when he accidentally hit someone in the head, when he swung the door open.