It proves that, at it's peak, deaths were running at twice the normal rate, at a level not seen since the ONS began to record data in it's current form ( early 90's from memory ).
That is the data, that's what your man was saying isn't entirely accurate.
Given Tramps said he thought deaths were a tenth of what's been stated, that's not my definition of "entirely accurate" , so that statement is clearly utter bollocks, unless you think it's a coincidence that record numbers of people died at the same time that a pandemic was wandering round the country ?
It may mean nothing and the number is still tens of thousands large sure , but they aren't accurate.
You're partly right, they aren't 100% accurate, and that's for two reasons.
Firstly, early on in the pandemic, doctors appeared not to be recognising COVID as a cause of death, so there was a gap of thousands of excess deaths over and above those recorded as COVID. No-one can ever know for certain, but it's highly likely that the vast majority of those deaths were COVID related.
Secondly, the ONS numbers will be the most accurate figures, so they show that recent COVID deaths, as per recorded on the death certificates, are less than the headline figures from the DoH, and that's because the latter include anyone who has ever tested positive, but doctors aren't recording a lot of those on death certificates because they don't consider it relevant.
So, early doors, the ONS figures underestimated COVID deaths by thousands and then, as time went on, the ONS figures will still be pretty damned accurate, but the DoH figures start to become overestimates.
Overall though, the ONS numbers are the ones which matter, but they don't need to scrap the DoH figures, they just need to measure them consistently across the UK.
If you think about it, and I know very few people do, the 28 day rule that Scotland, Wales and NI apply, although it seems a bit arbitrary, is pretty sensible. It will occassionally include someone knocked over by a bus, but it'll also occassionally exclude someone discharged from hospital who died of a heart attack brought on by COVID complications. Overall, they'll probably balance out.