Re: TNG Cold Equations Book 2, Silent Wpns Nic-Picks -- SPOILERS
I get your Harry Kim example, but the difference, Kim is working the NIGHT SHIFT whereas Chen was in command of the ship when it was orbiting Orion --- the motherland of doing shady things -- and that the main crew and UFP Prez was on the planet to boot.
When working the night shift when nothing expected was to happen (Yeah, I suppose all hell could break loose), but my point is I'd want at least one member of the varsity squad commanding the Enterprise when the rest of the team is on the planet surface and not just leave it to the JV team.
Picard has left the Enterprise in the hands of the Chief Medical Officer during an incident with the Borg. So nothing surprises me as far as his command decisions go.
"...the most elementary and valuable statement in science, the beginning of wisdom, is I do not know." - Lt. Commander Data, "Where Silence Has Lease"