For the FRA ? None - mainly because of governmental immunity. Especially if assessing fines is its selected method of enforcement, which is a discretionary choice. Liability sometimes results only if the agency itself has a clear mandate to take some particular action, with a date certain (as here), but absolutely no discretion as to what it is supposed to do- e.g., release a prisoner on that date.
For the railroad which has the accident ? Theoretically no different, even if said railroad is found criminally guilty for failure to comply (is there even such a provision in the RSIA ? I don't know - yet). The railroad will be found to be negligent any way you cut it - the difference is mainly procedural, how easy it'll be for the plaintiff's attorney to prove the negligence. Beyond that, the jury will be outraged, and likely to impose astoundingly large punitive damages - but that's just more of same, not a difference in kind.
July 26, 2015