He DID have that option though.
And he used his phone to arrange with his friends to escape out the window, smoke weed, climb on a school roof and get picked up by police at 4am.
He utterly ruined any trust.
But I need to give him more autonomy and trust?
I don't understand why people keep suggesting this.
Because if you give him the impression that trust is utterly ruined, then there is no coming back from that- and consequently no reason for him to change.
Teens are very dramatic ("where's the point, they'll never trust me anyway"), they need help to move on and start again.
Not saying for a moment that what has happened is your fault or that you haven't been acting reasonably- but at the same time, you need to find a way in which he can start again and believe in himself as potentially trustworthy, believe that if he does, then you will be able to draw a line across the past and not keep bringing it up.
I have no experience of the situation you describe, but I do remember asking the Crisis team how I could trust a teenager who had just taken an overdose. "Because if you don't, she will never be safe" was their answer.
I don't know exactly how you should do this, OP, but I would say from my experience, that when it comes to the really big ones, the standard punishments you'd use for minor infringements aren't necessarily the right answer: some things are so big and worrying that you just need to take the time to reassess and reconnect.