Police Action on the Orange Line

I'm on my way to rehearsal the other night when the train suddenly stays stopped at Back Bay. There's loud voices and a lot of rubbernecking. The conductor, a nice motherly sort under normal circumstances it would seem, is out leading cops back and forth, "I saw him throw it like a football the length of the car..." I hear her say at one point. It doesn't help that there's an insistent pan handler dressed in only a short leather coat on board. Finally we begin to move and she comes over the intercom, "Sorry about that, we had a police action...they threw a strawberry shake in the last car...sorry." I like that she took the trouble to let us know the flavor of the shake. I hear a cop outside "Isolate that car when it gets to the Hills!" Apparently they had trouble nabbing the strawberry shake hurler.