Their decision was probably based in some way (assuming it's based on available information, which is admittedly risky) in his marriage to a foreign national while expressing interest in moving to the states, and the embassy's reluctance to chance him violating his visa permissions and in some way moving here with his wife in a permanent resident-alien w/o a visa type manner. Not claiming to know anything special, bu…
The problem is that there is no due process for these things. You're always playing a bit of a lottery whenever you interact with, well, just about anything. But when domestic police screw up (or not!) and you get in trouble, there's at least a process in place that tries to smooth things out. It's still not a guarantee, but if you didn't actually do anything wrong, the process makes a decent stab at ensuring that fa…
Should the US treat visitors with respect and make the process of entering and leaving predictable and transparent? Yes. But saying foreigners have due process rights goes beyond should into must. And that is incompatible with our traditional views of sovereignty.