Having said that and based upon the allegations contained in the Complaint, it seems as though the Plaintiff is in the catbird seat. The Defendant would be crazy to let this case get to a jury.
This would seem to be the likely way it would play out, except it on the defense side it would definitely be worth the delaying action and possibly even some luck for them to try a few motions mentioning the arguments presented by peekay. It's worth noting that even if the ABX case is cited by defense, it is at best only a supporting argument and easily rebutted in a response. However, I would think it would be in the interest of Allegiant (and their council's legal bill) for them to drag out discovery and pre-trial procedures for a year or more and then worry about settlement.
They way he was dismissed is going to be a problem for the defense as the reason for his dismissal is given as lack of performance and that rationale seem to be quite suspect which will give the complaint plenty of latitude to suggest other reasons for the dismissal, any of which may be damaging under Nevada law.
Besides to suggest the application of Federal regs have no relevance under state employment law, especially when safety is involved, could possibly mean that many other professions from coal mining to medicine would be greatly affected. I doubt federal courts would want to start a string of precedence of employees being fired because... say for example they would not be willing to violate an OSHA statute...