Quite true, in it's final effect it did more harm than good in those situations. But it takes is one hot head who thinks he knows better to get an entire squad killed. And certainly the words and actions of his comrade who wanted to blow him up were just as wrong.
In the one scene (geheh...spoiler!) when he's disarming the car with all the shells in the trunk, he was wise to take off his gear and use his headset. With that amount of explosives in those shells it would have leveled that block - wearing lead armor is not going to do squat. But I did have a problem with him not responding even to let his squad know what he was doing. It wouldn't have cost him anything or even crimped his style just to let the guys guarding his back what he was doing.
But in the end he did get people hurt. Going off on that personal vendetta almost killed the specialist, not to mention the leg wound that could have been fatal (Black Hawk Down, anyone?). I know I'm getting into semantics, but I think the point still stands that you do what you have to do to get a job done, but don't push that line harder than you have to.