I don't like this one, but I kinda get it. It's not about Covid, it's about obeying orders. Troops either had to take the shot or apply for an exemption. Doing neither, is throwing your middle finger at your commanders.
The key is “legal”. DoD was forcing the to take the unapproved EUA jabs, not the authorized one. Courts have sided with soldiers that it was illegal to substitute the eua with the authorized. Hence an unlawful order - again supported by court decisions.
Dod also illegally issued blanket rejections of exemption requests - again violation of law and policy.
Bottom line - not about following “lawful” orders but all about damaging the military.