“In Katsigiannis v. Kottick-Katsigiannis, 2001 CanLII 24075 (ON CA), 55 O.R. (3d) 456 (C.A.), at paras. 46-49, the Ontario Court of Appeal stated:
46 The words “consent” and “acquiescence” as used in Article 13(a) of the Hague Convention should, in my view, be given their ordinary meaning so that they will be consistently interpreted by courts of Hague Convention contracting states. In any case, I can see no logical reason not to give those words their plain, ordinary meaning.
47 “Consent” and “acquiescence” are related words. “To consent” is to agree to something, such as the removal of children from their habitual residence. “To acquiesce” is to agree tacitly, silently, or passively to something such as the children remaining in a jurisdiction which is not their habitual residence. Thus, acquiescence implies unstated consent.
48 Subject to this observation, I agree with Lord Brown-Wilkinson’s approach and analysis in H (Minors), Re. When Lord Brown-Wilkinson said that “[a]cquiescence is a question of the actual subjective intention of the wronged parent, not the outside world’s perception of his intentions”, he was, it seems to me, really speaking of the wronged parent’s consent to a child’s removal or retention based on evidence falling short of actual stated consent. That is what acquiescence is — subjective consent determined by words and conduct, including silence, which establishes the acceptance of, or acquiescence in, a child’s removal or retention.
49 To establish acquiescence in the Article 13(a) Hague Convention context — “subsequently acquiesced in the removal or retention” — the mother must show some conduct of the father which is inconsistent with the summary return of the children to their habitual residence. In my view, to trigger the application of the Article 13(a) defence there must be clear and cogent evidence of unequivocal consent or acquiescence. In my opinion, the evidence on which the mother relies does not meet that test.”