No, she went INTO the school to get her phone, came BACK to the door, THEN called 911. THEN went back into the school leaving the door she opened, OPEN.
She probably heard the crash and went to investigate. Propping the door open so she wouldn’t get locked out.
It’s not her job to investigate a car crash.
It’s her job, in a lockdown, to stay with her kids in a locked room.