Other than past performance of the Mexican authorities when faced with similar well to do criminals.
I suspect they only sent Luster back when it became a "Big Deal". If he had been quietly turned in, they'd have kept him in Mexico, probably not a the same sort of facility that Chapman would have been put into.
You may "expect" that, and I can't refute that. We don't know. What we DO know is Dog was arrested, Luster was returned, and Dog jumped bail and fled.
While I like Dog, and wish him well, I can't be mad at my government for acting on a valid arrest warrant submitted through proper channels based on our current extradition treaty. This isn't like the case of the boarder patrol agents, no matter how much Tom Tancredo tries to link them.
In fact, doing so hurts the cause of those brave men.