Not even that most bureaucratically entwined bloc of nations on earth known as the European Community has yet managed to sort this out.
Essentially, disqualification from driving can only be imposed by a Court. It cannot be done administratively. A driving licence can be revoked by administration (the DVLA can do so under a number of circumstances). However, having one�s licence revoked is not the same as being disqualified. If driving after the former has happened only a charge of driving without a licence can be brought (maximum penalty �1,000 fine). The maximum penalty for driving having been disqualified is six months custody.
Courts being what they are, their orders (and driving disqualification is a court order) only apply within the area of their jurisdiction. So a disqualification awarded in Canada will not prevent a driver driving in Britain.
Similarly, disqualifications awarded in Britain are not enforceable elsewhere. Last August somebody called Caprice (whom I understand is a �celebrity�) was disqualified for drink-driving for 12 months. She was seen a few days later driving a 4x4 perfectly legally in (I think) Majorca.
Joe Public may well have difficulty obtaining insurance in these circumstances, particularly if they only hold one driving licence and that was issued in the country they received their ban. (Caprice, it seems, was not so encumbered). But it does not mean they are driving whilst disqualified.
As far as his driving record goes, no record of the Canadian conviction will appear on his British record. Neither British courts nor the DVLA are empowered to confiscate, endorse or withdraw licences issued by foreign administrations. A mechanism does not exist to record the decisions of foreign courts on British licence holders� licences or their records. Not even within the EC � yet.