Because on SM there were pics of certain places in both locations. And getting INTO Mexico by cruise ship is much easier than crossing the border in a SUV that everyone knows the description and plate number on.
Not saying they did but it would be extremely easy. If i ever have to get into another country quickly and safely while staying 'hidden', i'd most definitely go by cruise to mexico then go from there. You can then get to Belize or south and never be found. 4000 will go quite a ways that way... much easier than staying in the states or flying somewhere. The borders will be on the lookout for them. They would have been notified. NOTHING is checked by customs when you get OFF the ship in Mexico, you get checked coming back ON. People are saying he is very intelligent, possibly this was planned well to 'escape' together. He knew it was coming down on him, he took a CASH LOAN on his vehicle... that to me says he's willing to dump it somewhere.