The military is not for everyone, it works only if there is respect for authority and faith in others. What purpose does one get from refusing to say, so help me God? If one doesn't believe it then it doesn't mean a thing to go ahead and say it.
This man is a troublemaker and is not material to have others depend upon him for anything. This is my opinion.
Those English Catholics were troublemakers for fighting for 150 years to remove oaths requiring them to deny Transubstantiation and stating other Catholic beliefs were “superstitious and idolatrous” in order to serve in the Royal Navy or British Army or hold any public office in the UK.