I've been able to reproduce this bug under the circumstances I described, but not with a normal forward-progressing sequence in step-by-step mode.  It's obviously an incorrect statement being made by TurboTax, but I doubt it's going to be high on Product Quality's list of things that need to be corrected because it doesn't affect your tax return.

If you can identify a more straightforward way to reproduce the symptom than what I was able to come up with, I'll pass it along to the moderators here.