One of the single worst things that plagues military forces is the phenomenon known as "friendly fire." Some instances of friendly fire have been momentous, like the time Stonewall Jackson was shot by Confederate troops who mistook him for a Union general.
General "Stonewall" Jackson (Image from Wikimedia Commons)
There have been tragic, modern instances as well – like the case of Army Cpl. Pat Tillman.
Former Arizona Cardinals football player Pat Tillman. (Photo from U.S. Army)
This was also a problem in World War II — reference the disastrous friendly fire incident off Sicily in July, 1943. In trying to prevent these terrible instances, the Navy put forth a very unique training film, featuring the fictional "Ensign Dilbert."
No, this isn't the same Dilbert that's made Scott Adams very rich, although, Adams admits that the suggestion of the name was, in fact, inspired by a Navy character. This Dilbert is, well… an idiot. A real big one. The type whose sole purpose in life is to be a warning to others.
The moment when disaster strikes because "Dilbert" was careless. "Carl" had nothing on this guy. (Youtube screenshot)
The film was called, aptly, Don't Kill Your Friends. In the film, the main character, training to be a fighter pilot in the Grumman F4F Wildcat, looks friendly and likable enough, but he repeatedly makes bone-headed mistakes that could get people killed. It even features one disastrous incident with a supposedly "safe" dummy cartridge, which can do some very serious harm when it falls from a fighter plane.
Check out the film below, complete with a supposedly likable "Dilbert" and the chain of disasters he causes.