lotuseater
Explorer
Since it says that the command can't be directly harmful to it, I think a DM would be justified using it's action to Disengage and then moving. It really depends on the DM though. I'm not even sure how I would play it as the DM. Probably would depend on the group. The spell even says the DM determines how the target behaves, so it all depends on how the DM reads it.
IMO, dashing away, and thus inducing one or more attack of opportunities, is not directly harmful. It is indirectly harmful, as the action of fleeing allowed someone else to attack it. Direct harm would be stabbing yourself or jumping off a cliff. You might argue an experienced warrior might be aware that dashing away without disengaging leaves it open to attack, BUT in some strategic situations it makes more sense to flee without disengaging, despite the attack of opportunity. The fact it's a case by case basis as to what's the best form of retreat highlights the fact it is not directly harmful. I'd rule that fleeing pushes the affected creature to single-mindedly focus on that particular command at the exclusion of all else (including disengaging), as long as direct harm is avoided.