...he's not. This is why we cut to Mrs. Bob being led out of the hospital by the authorities, Team House arguing the myriad reasons she could have done it. No one will ever know. The episode is too close to over. Cameron comes to offer her cash to House.
And, back at House of House, the good doctor opens his refrigerator, removes a Post-It Note reading "Property of James Wilson. Trespassers will be prosecuted!" from something that looks delicious, and clicks on his home answering machine. One message tells House that Wilson's apartment could be lost to a better offer, but that if Wilson calls back ASAP, he could get the place back. House, his heart growing a size bigger every minute, deletes the message to keep his best friend around. Awwwww! Seems like a call that time-sensitive probably should have come through on the man's cell phone anyway.