Discharging a firearm to 'make a point' is NOT 'controlled'.
A SANE response with the same result.....turn it on and stick it in a bucket of water.
I'm not trying to be flip or sarcastic, but is this an anti-gun thing for you?
Would it have been better for you if he did it in a shooting range or similarly more controlled environment?
Personally, I hate guns. I will probably never own one. I have shot a pistol one time in my life and most likely never will again. I lost a job for turning in the CFO for bringing a gun into the office (Apparently he grew up with the CEO and had dated his sister). I hate guns. I also respect a persons right to carry one and use it safely.
Either method you list destroys the laptop. An argument could be made for either method being childish. Shoot it. Drown it. I suppose the daughter could shoot or drown the guys dog or cat in response if you want to go that route. To jump the gun and suggest 'shooting the brat' could be the next step could be seen as childish. Now if he tells her he'll shoot her next time (like he warned her he would do to the laptop) I could see your concern but he clearly stated what his next step with her was going to be. Honestly, this guy strikes me as more of a man who is not only thoughtful but a man of his word.
I don't see it as 'shoot something'. Punks, hoods, criminals, rage-a-holics, etc go out and 'shoot something' as a knee jerk response. This guy's main objective was to destroy and eliminate the laptop (his daughters method of expressing childish behavior) and his method was to use a gun instead of a bucket of water or a trash compactor.