Does the harmless-error rule apply to clearly erroneous findings of fact if a district court expressly based its credibility determinations (and its ultimate conclusion) on those errors?

If a fact-finder relies on errors of fact for its conclusion does the presence of other substantial evidence to support that conclusion make the errors legally harmless?

Given the requirement of "habitual residence," how does the Hague Convention apply to newborn children?

Whether the harmless-error rule applies when a district court expressly relied on clearly erroneous factual findings in its credibility determinations and ultimate conclusion