Rephrase the question:
Can something escape from a (standard general relativistic) black hole to infinity?
Can something escape from a (standard general relativistic) black hole to a finite distance from the horizon?
So the situation will be the following:
1)Alice is too far away (the train is very long), the ball doesn't reach Alice. In this option is the setup that it's impossible, Alice and Bob cannot pass a ball to each other if Bob is arbitrary close to a black hole horizon (at least without noticing).
2)Alice gets the ball and the train is short. Alice is now inside the black hole, by definition.
3)Alice gets the ball and the train is so short that it can be seen as a point. Boundary situation in which both Bob and Alice are on the horizon, but this makes little sense since we want a train with finite length.
The black hole horizon is a teleological objecs, you should really know the entire future history of the space time in order to know where it is. Of course this cannot be done locally. What happens when Bob gives away the ball (I guess) is that the horizon get deformed in some odd way to include Alice when (if) she gets the ball.
This nice article https://arxiv.org/abs/gr-qc/0508107 describe for instance how the horizon is deformed if some mass is falling into the black hole. An odd effect is that infalling matter can decrease the rate of expansion, while the horizon expand more if something it's NOT falling!