Trains *don't* come in that fast at South Station, or anywhere, for that matter. If someone got hit that way, he/she would have wanted it, and that's a different sort of story right there.

You might try to watch the next few episodes anyhow. I'm not sure if AD's scheduled to be in them or not, but I think there's going to be some building up to the season finale, and you do want to fully appreciate your whedonverse actors, don't you? :-P