[readittwice]

That article was clearly published in May 2020, I don't assume AZ sneaked that article in. Are you really saying that AZ was faking the press release in May 2020, so that in 2021 they could claim that the UK signed the contract three months before the EU?

[gebruikersnaam]

Your article from may doesn't say anything about signing contracts, only that they are ready to go.

I've seen the articles mention may, june and august as signing dates of the contract, so clearly there is some 'miscommunication'. And both the may and june date originates from AZ, while the actual date turns out to be august.

[readittwice]

There are plenty of articles from May 2020 that all discuss in various words that a deal was struck. If you believe that AZ didn't sign a contract with the UK before Aug 28 then the burden is on you to prove that.