Could he be full of the Holy Spirit?
He was to obey every law and ordinance of man as a Christian UNLESS that law is in opposition to God. In this case there is nothing wrong with a law that says military members are not to engage in political activities while in uniform. They are not to give the impression that the US military supports this political cause or that political cause. That's the reason for the rule.
He could have prayed in Jesus' name at that event in his civilian clothes all day long and all night long.
Instead, he chose to disobey a direct, legal order from an officer appointed over him.
He was not following the guidance of the Holy Spirit.