Dame Cressida quit after Mr Khan expressed his displeasure at her handling of outrage over racist, misogynist and homophobic messages shared by a group of officers based at Charing Cross police station.
Sir Stephen House said Khan had ignored proper procedure over Dick's departure, which instead "played out in the media".
"This is the closest Pointless has ever come to being taken off air," wrote Richard Osman.
From the newsletter: The ousted Met chief leaves behind a record of failure unmatched in British public life.
"Cressida Dick never broke the law. Boris Johnson did. Guess which one just resigned," James O'Brien tweeted.
The mayor said the Met needs to urgently show it has an effective plan for restoring the trust and confidence of Londoners in the police.
"Superb again from @ByDonkeys We have now lost all trust in the Met Police as well as government."
"We police without fear or favour," the Scotland Yard chief insisted.
Britain's most senior police leaders could declare their forces institutionally racist, it has emerged.