The writer, who grew up in Cannock, responded to viewers on social media as he shared research he says indicates the show's series finale was less divisive than generally thought.
Sunday night's episode of the BBC One series saw DSU Ian Buckells, played by Nigel Boyle, unmasked as the mysterious H, the corrupt police officer at the top of a criminal conspiracy.
However, fans and critics were split over the reveal with some saying they felt let down and others praising the decision to avoid a more dramatic conclusion.
Line of Duty chat has dominated social media since the show was aired and after at first staying quiet Mercurio responded to several tweets on Wednesday.
In one he compared a viewer to former Line of Duty baddie Jackie Laverty, saying: "Lorraine is the result of what would happen if Jackie Laverty's body parts were reassembled in the wrong order."
No way am I taking that from the Irish business journalism community after they failed to warn the Gaffer about the Kettle Bell development. He lost his missus over that scheme then got suckered with a massive bung of OCG cash. Shame on the lot of you! https://t.co/k3VpfknIWK— Jed Mercurio (@jed_mercurio) May 5, 2021
Some clarification on specific numbers has been requested. I'm not permitted to disclose the AI figures, however for LoD they are in the top tier of the range for BBC1 drama, including for the finale, and over 50% of those polled rated the finale as either 9/10 or 10/10. https://t.co/cAnZwn2Jzt— Jed Mercurio (@jed_mercurio) May 5, 2021
Mercurio replied to critic Peter O'Dwyer, who had accused the writer of "losing", by saying: "When it comes to losing, I have to defer to lifelong expert Peter O'Dwyer. What a f****** p****."
The targeted tweets came after he shared research based on randomly polled viewers rather than online aggregation sites suggested a "far less extreme picture".
He said the decision to opt for a "down" ending to the storyline had in fact alienated less viewers than social media suggested.
In a chain of tweets, he wrote: "No one disputes the Line Of Duty finale divided social media opinion but the audience research so far shows a far less extreme picture.
1. No one disputes the Line of Duty finale divided social media opinion but the audience research so far shows a far less extreme picture. We knew a "down" ending would rate less favourably with some viewers, however all 7 episodes varied by under 10% on average viewer score ...— Jed Mercurio (@jed_mercurio) May 5, 2021
"We knew a 'down' ending would rate less favourably with some viewers, however all seven episodes varied by under 10% on average viewer score.
"The research determines the episode ratings based on randomly polling viewers, rather than sites like IMDb where scores can be skewed by users strongly motivated to register their immediate anger/adulation.
"1000 random viewers submitted scores from 1-10 which have been used to calculate the Appreciation Index (AI) as a score out of 100. The AI for the 'down' finale was only seven points below the next lowest in Season Six (Ep 1).
"These figures won't stop the debate, of course, nor should they - that's still all part of the experience of shared TV viewing. Thanks again for watching."
We're honoured and flattered by the viewing figures for #LineofDuty6. We knew attempting to explore the real nature of corruption in our society wouldn't appeal to everyone, but we do sincerely thank you all for watching. It's been our privilege to share your Sunday nights. https://t.co/mDvNckFdAO— Jed Mercurio (@jed_mercurio) May 3, 2021
The much-anticipated finale was watched by an average of 12.8 million people, with a 56.2% share in overnight viewing figures, making it the most watched episode of a drama in 20 years, the BBC said.
Martin Compston, who plays Steve Arnott, revealed that he, Adrian Dunbar (Ted Hastings), Vicky McClure (Kate Fleming) and Mercurio had agreed to get "AC12million" tattoos if the show hit the milestone - in reference to the show's crime-busting AC-12 unit.
During Sunday night’s finale of the BBC One series created by Cannock writer Jed Mercurio, DSU Ian Buckells, played by Nigel Boyle, was unmasked as the mysterious figure.
Boyle, who grew up in Birmingham, said he was “buzzing with excitement” when he found out his character was the shadowy H.
The finale of the sixth series also left the future of anti-corruption unit AC-12 hanging in the balance after a series which saw Halesowen actor Gregory Piper play a key role as corrupt officer Ryan Pilkington.