It's so rare for Nitty to actually directly address controversy - usually she'll just ignore it. Think of the time she got caught saying Holly Willoughby was disappearing, or Julia slagged her off, or she was caught swearing when This Morning won an NTA. She'll just pretend nothing is happening until enough time passes that no one cares.
As others have mentioned, they were quite slimy about addressing it. They were playing dumb, and the conclusion was 'oh, we counted our households wrong because it's so confusing! but maybe we were in the right anyway... not sure...'. In reality, they know (or ought to have known) that you need to socially distance with any other household outside of your own anyway. I wonder if they'll ever address it directly again.
To be honest, let's just forget the rules for a second. It's just bloody common sense. Even if there weren't the legislation, you OBVIOUSLY shouldn't be meeting up with 2 different households without social distancing as you go off on a week's holiday (and that's forgetting the fact she's had Lisa & Dina over without distancing, of course).
If, say, Mark had the virus, he'd have spread it to Nanny Di, Dina's family, Lisa's family, Maddie's bf & his family, Kiki's friend & her family. Lucky that Nitty and Mark are such 'intelligent people'...
It's even worse than when Mark went off around London when lockdown started to take pictures and be arty. If everyone had such an idiotic idea, the streets would be packed.