Question: How did Peter and Ned get out of detainment in SMH?

In MCU, law enforcement officers and US soldiers are always supposed to be either corrupt or incompetent. Just look at the 1st Avengers movie. New York has been attacked by terrorists multiple times in the past so the Mayor and the NYPD should have a evacuation plan in place and should have all their officers trained to be able to safely and efficiently evacuate civilians in case of an emergency. But in the 1st Avengers movie, the NYPD couldn't evacuate civilians on their own and need Captain America to become a traffic cop and tell people where to run to.

MCU Dictator Kevin Feige wants to make law enforcement officers and US soldiers look bad so the Avengers can look more heroic. It's similar to how WWE sometimes has squash matches where a wrestler completely dominates and squashes an opponent so that wrestler looks like a really tough badass.