  We correct a mistake in a lemma in the paper cited in the title and show that
it did not affect any of the other results of the paper. To this end we prove
results on linearly disjoint field extensions that do not seem to be commonly
known. We give an example to show that a separability assumption in one of
these results cannot be dropped (doing so had led to the mistake). Further, we
discuss recent generalizations of the original classification of defect
extensions.
