Kick him off

You start to rapidly shake your leg in an attempt to get him off of you. Luckily, you manage to boot him right in the face, stunning him long enough for you to escape. You flee the room, leaving the zombie crawling after you. You shut the door and jam it in place with a chair. You look around some more before deciding the only way to get out is either the front door or the back door you came from earlier.

You hesitantly creep out of the staff-only area and start to creep around the food shops. You go from aisle to aisle, evading the zombies very well and having only a few close encounters with the horny dead. As you get to the entrance, you spot a bunch of zombies, around 8-10 of them, and you realise you can't get out.