Poor sceptics will be left looking pretty damn stupid once it's explained how Brueckner hid in the apartment before Gerry's check moving the bedroom door back & forth, then waiting around the place until after Matt's check before making good his escape out of the window & down the street past the Smiths whilst wearing a Gerry mask.
With a skinny bloke like Breuckner, it seems quite possible that he could have hidden in the approximately 45* space behind the door. End of wardrobe on one side, wall on another and the door making the final edge of the triangular space.
I remember Gerry once saying that in retrospect, he felt that there might have been someone in there.
Sorry, but am too old to waste time doing cites. Believe me, or not, it's up to you.
BTW, I think you got it in the wrong order. IIRC, Matt checked before Gerry Having expressed my opinion about this, even if there was space, it doesn't mean that Brueckner was in there. It is just a possibility that I felt should be pointed out..