Deliberate mistake: When Cochran sabotages the Jet Ranger helicopter by loosening the nut on the bolt securing the linear actuator governor, the bolt is inserted in the wrong direction. The bolt should have been heads up to prevent it from falling out as it did causing the helicopter to crash. Moreover, the linear actuator is on the opposite of the engine from where Cochran disconnected it. (00:38:05)
Deliberate mistake: The Army Sergeant that gives the Blue Thunder presentation's mustache is out of military regulations - much too thick and too long. (00:30:20)
Chosen answer: Murphy has been deemed a threat to the public at large by the authorities, having "snapped" and stolen an armed helicopter. Cochrane is using that determination as cover to finally kill Murphy, whom he's long despised. Killing Murphy on the ground would be harder to get away with. He would not be responsible for paying for the helicopter anymore than the Air Force or the other police helicopter crews would be had they sucessfully knocked Blue Thunder down.
johnrosa