I actually figured that the REASON for this "bug" was that because it clearly states that GUARDS AND DOGS will see right through your disguise.
So, when you first talk to Dawes, he stops you before you even step past the gate. He ONLY goes hostile once you are within 1-2 feet of him. I figure that's him going, "wtf? Wait a minute..."
I actually consider it a bigger bug that you can snipe Dawes, take his key, and waltz in to start the quests, no questions asked. The Ganger leader will actually say, "Yeah, Dawes said he let someone in." Did he now? Cuz he wasn't talking about ME.