What makes a gun easier to shoot intentionally makes it easier to shoot unintentionally. There are legal as well as practical implications to this.
Self defense is a complete defense to a charge of homicide or assault. It is also a complete defense to a civil suit for wrongful death or personal injury. An act of self defense is an intentional act. An unintended act cannot be self defense because for self defense to be established one must have reasonably believed them self or others to be in imminent peril of serious bodily injury or death, and to have acted out of necessity to prevent it. The act of self defense that provides a shield from criminal charges or civil liability is always a deliberate, intentional act based upon reasonable perception under the totality of the circumstances.
If you pulled the trigger when you didn’t intend to do so, it cannot be self defense. It might have been an “accidental” shooting, if there were such a thing. There isn’t. All unintentional shootings will subject the shooter to the possibility of some sort of criminal charge, even if only a misdemeanor. A civil suit will be likely as well, and might be the worst consequence [aside from the horrible knowledge that you have negligently brought grievous harm to another person].
Don’t ever modify the trigger of a gun carried for personal protection to make it have a trigger pull lighter than set by the factory when the gun was made. Not only will that make the gun more dangerous to yourself and others by enhancing the possibility of unintentional discharge, the act of modifying the trigger to make give it a “hair trigger” will give a plaintiff’s lawyer or a public prosecutor something to use against you in a courtroom should you ever have a gun “accident.” A jury will be less sympathetic to your side of the case making it more likely you will be convicted of a crime or have a large civil judgment entered against you.
Light triggers are for guns used exclusively for competitive target shooting, not personal protection. In that same regard, don’t get in the habit of cocking a double action revolver to shoot it in single action mode if you carry a revolver for personal defense. Most revolvers have about a 10-pound trigger pull in double action mode, reduced to about 2 pounds in single action mode. If you cock your revolver as soon as you perceive a threat but before you’ve made the decision to shoot in self defense, and you unintentionally discharge the weapon too soon, your self defense claim may be in jeopardy.
The nightmare of a criminal attack may be over in seconds. The emotional nightmare will last longer. The legal nightmare, if there is one, can last for years, even decades.
The issues and legal principles discussed herein apply equally to police officers and lawfully armed citizens. For a relevant case see: Santibanes v. City of Tomball, Tex., 654 F.Supp.2d 593 (2009). See also, article by Massad Ayoob, Ayoob Files, Handgunner Magazine, September/October 2014.