Im very suprised that the police didnt arrest your friend for willfull endangerment & the state prosecute him,where i live near detroit michigan if you do something like that YOU WILL BE PROSECUTED ,some years back i was invloved with something along the same lines where i did something very bad to a guy who robbed me at gunpoint,not only was i prosecuted i was convicted & sent to prison.
People should not do something like this no matter how bad they want revenge because most state governments will put the hammer to them.