Others have suggested - off the record - that Sorrell himself has decided it's time to cash in his chips. When he observes in his statement that his "family has expanded recently," he's being quite literal as, less than two years ago, at the age of 71, he became a father again. That, combined with a bleak outlook for the advertising industry in general and for WPP in particular, may have persuaded him that it was a good moment to take his leave.
These competing theories ignore the wisdom of Occam's razor, the philosophical principle which reminds us that we should sometimes back the most obvious answer.
With that in mind, it's useful to remind ourselves that we know nothing about the accusations of 'personal misconduct' and 'misuse of company assets' that he faced.
In WPP's statement they say that Sorrell's departure marks the end of the investigation, and that it "did not involve amounts that are material".
But, as Adweek have rightly pointed out: "the statement did not address whether those amounts and the allegations of misconduct were separate matters." Is WPP's press release designed to gloss over the seriousness of a non-financial allegation?
With both Sorrell and WPP hopeful that our curiosity will be sated by their statement, and with most of the press apparently content to let the matter lie there, it seems unlikely we'll ever discover what - if anything - has been swept under the carpet. But the suspicion lurks that it was something of sufficient gravity to force Sorrell to walk down a plank he has always said he would need to be dragged down.
It also makes it a vanishingly small possibility that we'll see any kind of comeback. Having interviewed him on multiple occasions, Stephen Lepitak is probably closer to Sorrell than any other journalist, but when he asserts in a tweet that he can "guarantee that [Sorrell] is far from done" we suspect his admiration is clouding his perspective. It's time to warm up the boiler at the glue factory.