At the end, did MTL have a sense of vindication

[STS Lincolnite]

Am I correct in remembering that the River Queen was a commercial vessel that was chartered by the War Department and captained by a steamer line employee (not the military)? If this is true, is it possible that Mr. Stackpole was a member of the crew of the River Queen (maybe the Captain's steward or some such position) and thus would not be listed as one of the party aboard the River Queen?