How important the event turns out to be, we will not know for some little time if at all. But the defection of Tory MP Sarah Wollaston
to the "remains" is certainly an event.
Dr Wollaston, chairman of the health select committee, has said Vote Leave's claim that Brexit would free up £350 million a week for the NHS "simply isn't true". And, with the campaign completely impervious to any kind of criticism, she has finally decided she does not feel "comfortable" being part of it.
When she first joined the campaign, Pete was less than impressed
and, compared with high profile recruits such as the flatulent Johnson, she has not exactly been in the front line.
But now she seems to be making up for lost time. In an interview with the BBC's Laura Kuenssberg, she says: "For someone like me who has long campaigned for open and honest data in public life I could not have set foot on a battle bus that has at the heart of its campaign a figure that I know to be untrue".
"If you're in a position where you can't hand out a Vote Leave leaflet, you can't be campaigning for that organisation", she adds, then rehearsing some well-lubricated "remain" propaganda.
"The consensus now", she says, "is there would be a huge economic shock if we voted to leave." Thus, she is able to reconcile her defection, arguing: "Undoubtedly, the thing that's most going to influence the financial health of the NHS is the background economy. So I think there would be a Brexit penalty".
She also says that
her 81-year-old father helped persuade her to switch sides by arguing that the EU had helped to keep the peace.
These views unconvincing as they are - are leading some to suggest that her original day-trip to Damascus to embrace the "leave" cause might have been somewhat contrived. Some are even accusing the woman of being a plant. Others, still less charitable, are discounting that but, noting the simplicity of her newly adopted beliefs, hold that she might have the IQ of a plant.
One also wonders how she manages to square her precious "integrity" with the different set of liars
she has joined, including a Prime Minister who has turned lying on the EU into an art-form.
Her beliefs, though, may be less significant than the fact of the defection. If the event doesn't pass as just a blip in the campaign, it could be a turning point. There has been growing irritation at the mulish obstinacy of Vote Leave and this could be the trigger that turns sentiment against them.
Either way, this is a huge own goal on the part of the official leaves. Their use of a fictional saving as the centrepiece of the campaign was entirely unnecessary and always bound to backfire. Now their resolve and strategic acumen (lack of) is to be tested, possibly to destruction with potentially catastrophic results - as they set about wrenching defeat from the jaws of victory.