surplus1
I think you will find that many juries know nothing of the subject of a criminal charge 99% of the time. Take Fraud for example, or a major train crash. The suggestion that someone can not have a fair trail because a jury wont understand it, is therefore not valid.
Its part of the proescution and defences job to ensure that the jury do understand the facts and can therefore make judgment on those facts. Again prosecution and defence lawyers/solicitors/barristers really should ensure that they understand before any trail. They have access to expert witnesses who can explain.
As regards to another point you raise, US citizens in other countries, like visitors from any country are subject to local laws. If you are a US passport holder and you steal something in the UK you would not expect to be immune from prosecution, any more than the reverse. If the law in a country says you can't do something, and you don't believe that law is correct or you don't consider thier system of justice correct, then don't go there, and if you do, obey those laws.
You mention Pilot Error, which is a loose term and has been pointed out is not a legal term. Any prosecution is going to require more evidence than that term. Not uploading enough fuel for a flight may well be pilot error, but its also negligence. That negligence may well be criminal, depending upon the circumstances.
The assumption that a pilot will refuse to cooperate with an investigation into an incident because he may face criminal charges, doesn't hold up either. There is nothing to stop a pilot who has been negligent being sued, co operation doesn't stop because of that. In any case, if you have done nothing wrong, why should you not be willing to co operate.