A more simple barrier at the entrance to the platform would be fine if there's a chance of a vacuum from a train doing such a thing to a buggy that maybe did have the brakes applied (but maybe didn't).
Platform edge doors are a totally over the top solution and would cost a fortune.
This was a chain of rather extraordinary events that came together and a barrier could be a good recommendation to reduce the risk, however small, in future. And that's it.
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