The whole premise of this being a ‘set-up’ is that at least one or both men involved are willing to spend years in prison...I don’t think so.
The actual premise was : "Noting that reports have Enright captured after injuring himself while escaping through the Cab's window, the next question must be: If he had escaped without being identified..."
This does not presuppose that the Muslim cabby was even involved in a set-up, but only that the perpetrated intended to escape.
In general, the premise of the vast majority of criminals is not that they are willing to do the time, but that they are smart enough to get away with the crime. This is true whether or not this was a false flag op.