I think the best advice given so far is that you should get the advice of an attorney. Your son has, from what I understand been charged with a criminal offense. Your son may also face a civil action regardless of the outcome of the criminal charge.
Both of these potential actions are grounded in state law. Since each state's laws are drafted/enacted by that state's legislature, there may or may not be any similarity to the laws of other states. This means that the only legal advice worth anything is advice from an attorney in North Carolina. Furthermore, I know of no state that requires laws to be enacted with common sense in mind. In fact, some laws may make no sense at all, common or otherwise.
Thus, the advice of an attorney is important when such things are at stake, since the common sense response may just be what sinks your ship. I have watched too many times as defendants give up the farm just as the judge is about to let them go.
Whether in civil or criminal matters, in most instances the charging party needs to be "put to their burden." In other words, they have the burden of proving their case by presenting enough evidence to convince the judge (or jury) that the alleged event actually happened. Thus, one should rarely offer to pay damages at the outset unless operating under the advice of an attorney.
Having said that, it is ultimately your choice as to whether to seek the advice of an attorney. If you or your son have homeowners or renter's insurance, they may cover this as a negligent action (read your policy, and again, consult with an attorney). You may have received good, common sense advice here. However, in court, all advice you receive (including mine) is worth little more than what you have paid for it.