Civil Servants have to be careful with their SM. My husband was a CS and he wasn't allowed to broadcast it. They're not supposed to get into political debates or comment on political things especially not something they/their department work on.The ONS person is tweeting from their personal account, so pretty sure they should not be acting as though he is speaking on behalf of the ONS.
Didn't some random from the Trussel Trust go off piste with the nasty tshirts which caused all sorts of problems when it was taken as a seal of approval.
I don't think that squig was from ONS and if he is then he shouldn't be talking about the report.