That would be a fair point, for anyone else. The Soldier looks past Bruce's shoulder again, the steady gaze registering, and considers for a long moment whether to give him a real, true out. It would show Bruce that the Soldier meant to be an ally, perhaps, but it could also dangerous. It doesn't think Bruce is particularly interested in gaining power over people, or he wouldn't be hiding like this all the time, and nothing about the boy's demeanor or actions here suggest he's particularly sadistic-- but it could be wrong. Trust is hard when you've been literal property for a lifetime.

After that moment, still not looking him in the face, it finally makes the admission. "You don't have to. Technically. You aren't a handler. But I do still take orders from other people. If you order me not to come here again, and not to tell anyone you live here, I won't." It won't be the steel-clad obedience of a handler's orders, but it'd be enough, combined with the certainty that Bruce wanted nothing to do with it, to keep the Soldier quiet and out of Bruce's way.

And now they find out just how much Bruce values his secrecy: enough to breach the Soldier's (admittedly limited) sense of free will, or not?