At the beginning of this thread it was reported that no overdue action was taken for a number of hours. Not really surprising with the number flight plans, both in and out, that Le Touquet have to deal with...not an excuse a fact.
More than likely someone in the UK phoned the UK Police when they couldnt get hold of him and Plod therefore opened a missing person file and alerts the various rescue authorities.
I suspect nothing more sinister...but Im sure some will wish to hype it up for all its worth.