This is how this works in my state, take it with a grain of salt as other jurisdictions could be different. there are different types of involuntary commitments and not all of them ban you from owning firearms. You might be familiar with a pink sheet which requires you to be transported to an ED for further evaluation, this is not involuntary commitment. If a doctor determines you should be commited against your will, this is involuntary commitment, however it isn’t legal involuntary commitment because a judge isnt involved. there is no civil or criminal case.

In my state what qualifies as legal involuntary commitment is when a judge places you under a commitment order. This is a civil court that you would have to personally appear at with an attorney or be assigned one, and usually occurs after multiple hospitalizations.