I’m not sure about this. No doubt there will be images emerging (like Starmer’s beer), but I would think that Labour would be much less cavalier about this stuff, simply by not being hooray Henrys who think rules are for other people.
Lots to criticise Labour for, not least their pointless internecine fights about trans rights while there is a global pandemic going on, but I suspect they won’t have been caught doing as much partying.