This was the rider's first public appearance in Britain since a very ordinary performance on Swain in the Breeders' Cup Classic which quite possibly cost his mount victory in the richest race ever run, and for the first time in his talkative career, the words did not come easily.
Non-subscribers to Sky Sports may still not have seen last Saturday's Classic, in which Swain was going as well as anything on the turn for home. By the time he passed the post in a close third place, though, Swain was practically running up the stands' rail, having drifted yards off course down the straight.
All the while his mount was drifting right, Dettori continued to hit him, head down, with his whip in his left hand, even though every fresh stroke seemed to increase his problems. To say the least, it was not the sort of alert, sympathetic ride which British punters have come to expect.
When he returned to the winners' enclosure, Dettori explained that Swain had swerved away from the bright television lights positioned by the winning post.
Yet Swain galloped into a similar blaze of lights when he finished a short-head second in the Dubai World Cup in March, and that day he ran straight and true. Punters who had seen their money turn sharp right - when it should have gone straight on - felt that they deserved a more convincing explanation.
But it seems they will not get one, from Dettori at least. When asked about the ride yesterday, the jockey refused to elaborate, which would be standard procedure for many riders but in his case is pretty much unique. ``I'm here to talk about the video,'' he said several times. ``No comment.''
Peter Burrell, Dettori's media relations man, added that ``the Breeders' Cup is history and we want to move on''. In truth, though, Dettori might have been better off talking about last Saturday, rather than concentrating on his new venture.
Even by the fairly low standards of most racing videos, this one is very casually put together, an assortment of offbeat clips which have been played to death on A Question of Sport, familiar scenes of Dettori's greatest moments on the track, and a surprising number of shots of horses, riderless and otherwise, galloping into solid objects.
These were presumably intended to be either exciting or vaguely amusing, but you have to wonder whether Walter Swinburn, for instance, would see the funny side. If this is supposed to promote racing to a new audience, they will get a very strange idea of what the turf is all about. Dettori denied that any of the video was in poor taste and maintained that no horse on film had been fatally injured.
Dettori is doing the media rounds this week, with an appearance on TFI Friday and a series of radio interviews. So will Chris Evans dare to ask him why he appeared to make such a hash of the world's most valuable race? Don't bet on it.