I just don't see what could have been done to allow Cobb to go home. It wasn't that he needed some kind of inception done on him, it was that everybody thought he had killed his wife. He was wanted for the murder, wasn't he? Inception would have had to have been done on everyone involved, including the police.

That having been said, we do see the top starting to wobble in the end, which it didn't do at any other time in the movie when he was dreaming.