Look, even in the reverse situation, if I lived with my mom and she was missing late at night, and I couldn't get ahold of her? I'd be worried as hell. Then if she came home late and said she was with some stranger at an undisclosed location? I'd be pissed off. The age of people involved is literally irrelevant.

This has nothing to do with being "controlling" or acting like they're property. It's expecting a baseline level of consideration to your family. That's really not asking much.

All this girl had to do was "hey, mom, I'm meeting someone for a date over on 1st street. I'll be back at 11". But she didn't. Then, all she had to do was pick up the phone when her mom called (twice). But she didn't. She actively went out of her way to instigate this situation, and her mother is rightfully upset about it. You don't "positively reinforce" an 18 year old when purposely go out of their way to fuck up, she's not a 10 year old running out into the street without looking both ways.