It seems unlikely we'll ever know the truth with any certainty. Obama has had a long time along with very powerful associates at his disposal to adjust whatever history needs adjusting. At this point there is simply no way to have any confidence in whatever is presented true or false.
I think you can only go back to 2008, where the truly altered COLB was put online, and conclude that if the current document was available to them, they would have used it. It would have provided an excellent platform to attack mccain (who as I understand was born about a mile outside the canal zone, in amador guerrero hospital in Colon, Panama).
The fact his colb appears now (2011) means nothing, he is the most powerful man in america and if he wants a colb, it will exist, and forensically it will be a world-class job. Only the document number could eventually lead to a problem, and one can only assume all necessary measures have been taken to ensure that this does not occur.
I personally agree that he was forced to use the new colb earlier than intended due to trump and the corsi book.