Yeah he did that to us too. First if you have a sniper, you can shoot him over the little wall (when you jump down and you don't have to put yourself completely in the open) and he kinda just stands there. Second if you really wanna 'lure' him, you can shoot him in plain sight. This isn't recommended though. He followed us a few times and then promptly goes back, but some other times he teleports to right on top of you and melees you. Not good. But frankly with sniper bullets and rockets from ammo synths it doesn't take very long at all. It's just the adds and invisible vandals you have to worry about.
The only reason we did the entrance was because we heard mixed reviews about the hiding under the platform