Joyce called 911 from her cell phone.I admit to playing "armchair lawyer," but with the knowledge that this girl had a cell phone, I would say she demonstrated poor judgement in pulling the emergency lever instead of calling for assistance first. In fact, if I were the T, I might even go so far as to push the point that there was no actual emergency, and that pulling that lever was as wrong as if it had been done on a train in the subway.
I will however, also admit that to the average person, being "trapped" in a train might cause a certain level of panic, although if I had been in her shoes I probably would have reacted in a much different manner (I would genuinely enjoy a ride around the yard at Riverside, but that's me ).
All of that being said, I agree that once that lever is pulled, the car should not be able to be moved until the lever is reset, and even then, a manual shutdown and restart of the whole train should be necessary to reset everything.