Except the military on Ord Mantell is as corrupt as it gets. The high ranking officiers blackmail their subordinates, it is mentioned multiple time that without a lot of bribe money the soldiers don't do anything, people get beaten up regularely for minor reasons and lets not forget that some of those military people get a thrill out of seeing refugees blow up in a minefield. Not to metinon that some of them are even traitors (Havoc squad).
So I ask you: Why should we believe any word out of the mouth of said fellow soldier? He is probably as unreliable as the thief.
Because it is the military's medicine. That's in an undeniable fact. The thief stole it. That too is undeniable. The thief has already shown she is to be distrusted. As for the military being corrupt, not all of them are. Jorgan wasn't. That private who asked for your help with his lieutenant wasn't. The officer who you reported that sick game with refugees wasn't. There is no reason NOT to believe your own people.
But then, that's wholly irrelevant. The medicine does not belong to the thief. She has no right to it. The refugees have no right to it. It sucks that they need medicine, but it's not right for you to steal on their behalf. That the game makes this the "light-side" option is awful.