[Dueller]

Hmmmm. I suspect there's a bit more to the story. Employer is being quite mum. I don't think its the fact that government employees are "at will" employees (normally only applies to political appointment positions). Usually pursuant to due process requirements (i.e., job is considered a property right), at least with regard to permannet employees you can only be terminated for cause(as opposed to temporary or probationary employees).

In any state or federal position you must take a loyalty oath that you will protect and defend the state/federal constitution against any enemies, foreiign or domestic. If I hadda guess his activities within the organization were construed as violating such allegiance/loyalty requirements.