The problem is that he hasn’t had an opportunity to plead his case.
Good law enforcement officers regularly make honest mistakes. Courts are a safeguard against this.
Imagine that you get caught up in an immigration raid. Maybe you were at a Mexican restaurant. ICE shows up and half the staff quickly sit at tables pretending to be customers. ICE arrests everyone, including you.
Will ICE let you go home to go look for your birth certificate? If your wife hires a lawyer what process will your lawyer use to present your birth certificate to ICE?
Due process and the rule of law protects you from the arbitrary power of the state.