Telegraphing the punch
Probably let a lot of bad guys sneak out with the evacuating civilians, but saved many, many civilian lives. An alternative would have been a surprise bombing attack that would certainly have caught the insurgents flatfooted, had zero American casualities, and also killed thousands of Iraqi civilians.
Now where would you draw the line?
As I have said many times before, our chosen tactics in Iraq are essentially trading American military lives for Iraqi civilian ones. If you don't like this approach, suggest something else.