Fwiw, you have scheduled flight plans and if a pilot did this deliberately they'd be reprimanded hard. You also have to land international flights in designated airports that have immigration. This wouldn't be easy to do if you're both wanted and bankrupt!
Someone like Sunny can't realistically just drive to and walk across the border.
There is a lot more to the DHS apparatus than simply scanning passports. Most of it is unseen by the public.
Now I know the government must surely have these systems but I think it may be doubtful how effective they've set it up to be to stop people leaving the country if by foot. The flow of people leaving the border in general is just way lower scrutiny, in my experience living in a border state. I would be shocked if the average say non-violent felon fugitive has much trouble leaving if they're not on a flight manifest.
How does the USA treat that in general? Do the people accept it, or praise it? Do they try to trick you into admitting legal problems with it? You can get back into the USA so I assume you must be a citizen?
What's your opinion on the general legality of fighting in a foreign war by choice?
Did you accomplish enough that you'd do it again?
I'm pretty sure there's thousands a day that walk into Mexico everyday without a passport. Hell half the people in line returning to the US claim they "forgot" theirs.
Leaving is easy without a passport. And don't forgot if Sunny can get to the shores of Pakistan, he is a citizen and they must let him in, after which he can easily hide in the tribal areas. All he would need is a yacht somewhere on the multi-thousands of miles on the coastline and some friendly boats in int'l waters to refuel him.