Just wanted to intervene real quick.. I have read through this thread and have some regulatory experience and knowledge.
First, we need to remember the field is no place to argue with law enforcement. You guys need to understand that any sworn member of any agency can commence the first step of a very long and uncomfortable process. It doesn't matter if the enforcer is outside of their jurisdiction, making an unlawful arrest, infringing upon regulatory code or even violating their own departmental policy. If they decide to arrest you, who is going to stop them? Your defense to have the case dropped, dismissed or acquitted comes later. In the meantime, you've been pulled out of your locomotive, arrested, potentially suspended, embarrassed, cuffed, possibly shackled, thrown into a police car, hauled to a secure warehouse where you can expect the corrections staff to handle you as a dangerous felon and insignificant member of society, strip search you, lock you in a cement room and generally house you with people who actually deserve to be there. And that's just the beginning. Should you continue to argue with the police officer, you'll find yourself tasered and in a restraint chair. All of this because you challenged a law enforcement officer. Federally regulated or not, the best thing to do is just comply when possible. In cases where you're forced to comply with the order, liability from that point forward actually lies with the law enforcement officer who issued the order. If any police officer tells you to move your train and you respond by telling him moving the train would be unsafe and your response is supported by the controlling dispatcher, and that prompts the police officer to command you to move that train or you're going to jail, then move it. But if that train derails or something bad happens that affects railroad property, public safety or life, that police officer could be held criminally and civilly liable. While there are statutes in most states that exempt law enforcement from such liability, those same statutes usually require a nifty little element called good faith. Police officers are just as responsible for their actions as you are. Expecting that accountability to be upheld in a smaller capacity might be unrealistic at times but in a situation where a freight train derails or someone gets run over because of that police officer, I would expect railroad police to intervene, investigate and charge that police officer accordingly with crimes ranging from criminal trespass to endangerment and quite possibly elevated assault, manslaughter or even murder. Again, police officers can make whatever decisions they so desire but their actions are not automatically immune from prosecution. Responsible members of law enforcement understand this but those who are egotistical, arrogant and want to lock up the entire nation will unfortunately, at some point in their career, learn the hard way. These are the guys that act out of personal interest or sequence and wind up being shot because they artificially manufactured danger. You can profile these individuals because they will argue you with every step of the way to show their superiority.
Anyway, be sure to keep your dispatcher or manager abreast of the situation detail-for-detail. The more involvement the better. I do not know the inner workings of railroads in the sense of how they support engineers in these types of situations, but I would definitely be in touch with the railroad police and share my experience after completing my trip. I would also ask my agency to intervene by contacting a superior officer of the local or state agency if the order caused undue jeopardy, was unlawful or just wrong. Initiating agency-to-agency communication is a better option than arguing with a police officer in the field. I respect all responsible members of law enforcement but I have no care for those who abuse the job. These are the guys that head to Mexico on vacation and show their badges when they do something wrong expecting what they call professional courtesy. Any reasonable local or state police officer would consult with an engineer about moving his train rather than throw around an uninformed order. It would be a much wiser response than issuing commands for the purpose of control especially since most people including cops have no knowledge/experience with railroad operations. Now if the engineer wants to challenge the police officer, you can't reasonably expect that police officer to stand down. Unless you have railroad police in your presence making the matter an agency-to-agency issue, that will not happen. Always try to handle these incidents post-compliance if possible. It's much easier and much more effective. Cheers.