I think not.
Crow is in fact, the best guardian I have observed (among the NPCs).
People who have never been soldiers might be inclined to think following orders without question is expected of every soldier. The actuality is a little different than that. As a member of the Armed Forces, we are swear an oath to follow any LAWFUL order. In a military court, claiming to be 'following orders' will NOT excuse you from a crime you committed. This distinction is made clear to us in basic training.
Crow was really doing the right thing. Method matters. Torturing the hive for information was NOT the right thing, not the Vanguard way. Zavalla said so himself! Zavalla should never have agreed to Caiatls pressure. It was weak, stupid and demonstrates how ill suited for leadership Zavalla truly is (not to mention self appointed, as are all the so called 'leadership' of the Vanguard). Crow did what he thought was right, and stood by to pay what price he must for his actions.
I respect Saladin for intervening in the way that he did. Respect his resolve and bravery at least. His intent to preserve the Cabal alliance that he thinks we need.
Personally I see the Cabal as just another group of f.o.s. conquest focused idiots. Their arrogant stupidity is easily as much liability as their so called might is a boon.