I knew someone who was due to return to the UK after many years as an ex-pat in Hong Kong...
When enquiring about the cost of car insurance, he was alarmed to be told that his absence for so many years would rule out any no-claims bonus.
Beagle, Strangely enough, I was in a similar situation (but not working for Cathay) and I had no problem keeping my NCD, including that accrued during the years spent driving abroad. I did obtain a certificate of maximum no claims before I returned to UK; perhaps your friend didn't do the same?