It is a pity, because he ought to have gone on a point of principle, and he was expected to do so.
But his conduct towards Diane Abbott has made the position of David Davis untenable.
When the defeat of UKIP at Stoke Central has marked the end of any pretence that the British political spectrum extended any further right than, say, George Osborne, then the fatally wounded Davis will be counting the days.
Like that of the scandalous Liam Fox, Davis's office exists only because, while Boris Johnson had to be given something, he could not be given anything important.
Johnson has responsibility neither for international trade nor for relations with the EU. What, exactly, does this Foreign Secretary do?
Abbott, meanwhile, has spent this week attaining a status not far from that which was enjoyed by the late Queen Mother.
Can you imagine that something like Newzoids will now depict her, if at all, then in anything other than the gentlest, and even the most downright affectionate, of ways?
Never mind the BBC or Channel 4.
Anything else will be confined to the comments threads of the worst right-wing websites.
And after the result at Stoke Central, who will even read those websites anymore?
The most swivel-eyed hatred of Diane Abbott that I have ever heard came, back in the day, from Neil Fleming.
He hated Tony Benn in the same visceral, uncontainable way.
Whatever became of Neil Fleming? He would have been 40 next month.