See my other comment, up a few times then down the other branch, the one with the pastebin code.
However the example with the two doctors was not the halting type.
Can you agree to that? Or do you have a defense of non-halting stopping rules, even though they are incapable of reporting some data sets?
I think I figured this out but would be interested in criticism on this point if not. Is there some way of dealing with non-halting that makes it OK?
The book says if there's a stopping rule then inferences must depend only on the resulting sample but that assumes there is a resulting sample -- that the procedure halts.