After sleeping on this issue a little, I've made some progress.
The errant -updateChangeCount: occurs when an attribute of the object in
question, which is nil to begin with, is re-set to nil. This setting happens
when a detail view gets bound (Cocoa Bindings). I'm still digging into why
that
I launchd my Core Data document-based app 24 times. Each time, it opened the
same document. 11 times, it worked fine. 13 times, it immediately set
-isDocumentEdited to YES. This causes a problem in my app (long explanation
omitted). In any case, it should not happen.
I overrode -updateChan
