This is not a matter of authority. It is a matter of being aboard a spaceship.

[Artanis wasn't entirely sure why he was explaining himself to a stowaway...but hey. Maybe he could defuse the situation.]

Space is a harsh environment, in such a way that even the simplest of mistakes, or negligence, will invite death. As commander of this vessel, it is my duty -- my obligation to the people aboard to ensure that no harm comes to them or this ship while we are in space. That is why I sent six warriors in here.

[Even now, he has half a mind to send a message to Rohana. She could dispatch a few sentries to the cargo hold in order to further ensure security.]