You make the assumption that it’s Davy in there, the man Metcalf told you about. You’re not particularly brave at the best of times, and you don’t like confrontation. And while you fully realise the consequences of your actions, you know you’re not going to throw Davy out into the cold, wet, windy dark now. You’re going to do that a five in the morning when, hopefully, it’s stopped sheeting it down and there’s some light in the sky.
Your first night on the job, and already you’re breaking the rules, and not just a little bit, but a lot. Enough to get you fired. And you know that he’ll be back tomorrow night, and the night after, expecting the same treatment. He won’t get it: you’ll throw him out. But you’re not going to do it tonight.
You back away towards the stairs, hoping that it’s going to be okay. You are, however, not completely daft, and you’re not going to risk him wandering around the rest of the building. There’s a lock on the bottom door, and after a few minutes with the keys, you find the right one, and turn it once you’re through.