About your point, if an international incident isn’t a legitimate reason to fire someone, I don’t know what is. And by extension, what kind of rights you are advocating.

It might be more appropriate to take action against the system that let the error happen. But there are two ways to reduce errors. 1) improve the system, and 2) raise standards for the employees using the system. Cost/benefit analysis ensues.

If you tend to believe him that this was an honest mistake, or even just that there's sufficient doubt, then the conclusion would probably be that he shouldn't have been fired, and his having been fired becomes a question of "how could this happen". And to this the (my) answer is "insufficient workers' rights, allowing a company to take an easy way out at the cost of an individual".