Gervais -- who'd already run into controversy earlier in the year for repeatedly using the word "mong", which he claimed, rather unconvincingly, was no longer used as a term of abuse directed at people with Down's syndrome, and then compounded matters by taking an inordinately long time to admit his error of judgement -- rejected the criticisms.
He denied the character is supposed to be mildly autistic, or indeed has any kind of mental disability. Derek, he said, is simply "not that bright". He's "a funny little nerd": an innocent who views the world "differently" and tries to see the good in people.
Once Derek was finally shown, some, though not all, critics changed their tune, conceding that the programme was warm, sweet, gentle and compassionate -- not characteristics you'd normally associate with Gervais' comedy. The closing scenes, where Derek struggles to accept and cope with the death of an old woman to whom he's become especially close, were genuinely moving.
And now comes Derek the six-part series, with Gervais once again writing (without partner Stephen Merchant), directing and starring. For what it's worth, I don't think Derek mocks the mentally disabled. I don't think it's offensive and I don't think it's meant to be. The real problem is it's just not very good.
The pacing is slack and the material painfully thin. The mockumentary format that worked so brilliantly in The Office -- and which has since been purloined by countless other comedy series, including Modern Family -- feels worn-out, a stale and unnecessary adornment that adds nothing. Derek would have worked just as well (or as poorly) as straightforward filmed comedy.
Most damaging of all is Gervais' performance. He was great in The Office, where he basically played himself. Even in his next best series, the excellent Extras, he didn't seem to be straying too far from his own personality. But he's not what you'd call a versatile actor.
As Derek, he shuffles around as though he's wearing lead slippers, his jaw jutting out and hanging slackly open, gurning at the camera and forever running his hand across a greasy, flattened comb-over.
He's outshone at every turn by Kerri Godliman, by far the best thing in it, as Hannah, who runs the care home. Even Gervais' regular sidekick Karl Pilkington, who plays stroppy caretaker and handyman Dougie, comes off better.
In its attempts to demonstrate its compassion, Derek often stumbles into mawkishness. "Is he handicapped?" a patronising council official who wants to cut the home's budget asks of Derek. "Yeah," replies Hannah, "he's too nice for his own good."
Derek earns an extra star for Godliman, and for not being as bad as Gervais' previous effort, the appalling Life Is Short.
There were better laughs to be had in Coronation Street where, in the unlikeliest plot in years, posh conman Lewis (Nigel Havers) continues to seduce dim-witted, pigeon-faced Gail (Helen Worth) with a view to fleecing her in revenge for breaking up his relationship with her mother, Audrey (Sue Nicholls).
Watching the two of them smooching is like observing a stick of organic Marks & Spencer celery attempting to copulate with a Tesco value-brand onion.
Meanwhile, over on Midsomer Murders Martine McCutcheon -- whose career path went from EastEnders to Love Actually to My Fair Lady in the West End to advertising pro-biotic yoghurt -- was bludgeoned to death with a giant wheel of cheese, yet managed to incur not so much as a smudge to her mascara. Someone is having fun.
Coronation Street 3/5
Midsomer Murders 2/5