The physics in the crawl space don't line up with the rest of the restaurant. At one point we see Bob stick his hand though a vent such that his arm can be seen by others. The vent is right next to the bathroom on the left (Bob's right); however, when we see him inside the crawl space, we see the void extending through where the bathroom should be.
When Bob is hallucinating in the bathroom, he switches between clean shaven and unshaven.