The relative nature of people's sacrifices is a red herring that works to the advantage of BJ and his like. It's tempting to say children's birthday parties are not vital, or not as vital as x,y, or z, but that just distracts us from what matters.
What matters is that BJ and his Cabinet set out very stringent rules for the whole population, stated clearly that everyone needed to follow them for the greater good, allowed the police to fine those who didn't follow them, sometimes for behaviour where the risk to the greater good was clearly minimal, and that all the while he and his staff were blithely organising BYOB parties to make the most of the lovely weather, shagging around and generally not making any sacrifices whatsoever.
Yes, they were working together on the same premises: so were NHS staff, who were suffering badly, putting their lives at risk, unable to see their families for weeks on end, and they weren't "spilling outside", organising BYOB parties in the sunshine.
BJ and much of the current, purged Conservative party doesn't give a shit about the greater good or about the effects of lockdown on the entire population.
What matters is that no one who got that email or heard about it had the guts to blow the whistle, which is an alarming indication of how deep the rot goes and how cowed civil servants are.
What matters is that the media must have known about it, but sat on it.
What matters is that if this doesn't do for BJ, it's hard to see what will.
What matters is that people are still sufficiently unaware of the deeply undemocratic nature of UK elections to think that BJ was elected by a majority of the population and presume that means he has carte blanche.
The Tory party release plenty of dead cats, to distract attention from the deeply undemocratic legislation they are pushing through and which will be very hard to unpick in years to come, without the relative significance of birthdays and funerals adding to that list.