That’s not actually true. It’s just very restricted, the contracts and laws around your service make it very hard. You can’t sue for things that are legal orders and you generally can’t sue specific people. You can absolutely sue the DoD for things like breach of contract. For example if you were processed out of active duty normally, on time and everything, and then were arrested for desertion a month later you would likely have a case against the DoD. It just has to be off the wall stuff like that.