In most places purposely concealing your identity is a crime
Concealing identity consists of concealing one's true name or identity, or disguising oneself with intent to obstruct the due execution of the law or with intent to intimidate, hinder or interrupt any public officer or any other person in a legal performance of his duty or the exercise of his rights under the laws of the United States or of this state.
He may have a little culpability in his being detained if his attitude was 'go away I am not doing anything' with officers responding to a complaint.
In most places purposely concealing your identity is a crime
100% false.