crab__rangoons t1_j2ce770 wrote

Rian Johnson addresses this in an episode of Scriptnotes.

Miles only drugs Andi and sets her up in the garage with the car running so she’d asphyxiate. He never actually kills her himself/sees that she’s dead. Since they never announced her death publicly, Miles never knew for sure if his plan worked. This is all mentioned in the movie but it’s definitely possible to miss.