I think that the testcase will probably need to be a little more elaborate than that to reproduce the problem. Per the initial report, I think you'll need to:
kill B and C (so that A sees [A], and D expects to see [A, D] but this never gets installed)
possibly, also restart B and C (so that A sees [A, B', C'], and D continues to be stuck with [B, A, C, D])
I think that the testcase will probably need to be a little more elaborate than that to reproduce the problem. Per the initial report, I think you'll need to: