(Bug found in Link16 work. Reproduced in tests test_choiceSlotAmbiguous1 and test_choiceSlotAmbiguous2)
Consider this choice:
Now imagine a subsequent expression containing ../C.
Which C is that? The first or second. Answer is it depends on which discriminator was chosen.
If the first discriminator is true, then the path ../C succeeds. If the second discriminator was true the path ../C fails with no such element C.
This is probably due to Daffodil's schema compiler assigning two different slot numbers to these two C elements, rather than recognizing they have the same name+namespace and so using a single slot for them.