Extra study time in lockdown ‘may have driven rise in firsts’

Yes and in most Universities students were given 24 or more hours to replace a 3 hour exam and students had full sets of notes and solutions ot exercises in front of them.....very strange this is not mentioned in the above article !

Also various mitigations were added under no-detriment policies meaning that students achieved higher overall averages. Arguably these would have a bigger impact than curtailed social activities

I'd like to see the data on which these conclusions are based. The link to the briefing that is referenced does not seem to work. Who knows, maybe there is solid empirical evidence behind those claims. But from personal experience at my University I can say that the no-detriment policy means students get a third and sometimes fourth attempt if they fail, the grades of whole modules will be automatically increased if they are lower than other modules (without consulting the module convener), extensions are given without asking too many questions, and the plagiarism offer looks the other way as soon as the alleged plagiarism quotes some sort of adverse circumstances. Meanwhile customers who show up to only a quarter of the seminars and are barely literate get a 2.1 degree. But these are just some subjective observations; I'm sure the rigorous evidence base built for that briefing document will leave no doubt that no such thing is going on and that it is indeed more study time that accounts for higher grades.