The 1st of 3 clarifications, that UKMIS didn’t brief ministers, could be interpreted 2 ways: broadly, meaning there were no briefings of any kind, from officials in or outside of UKMIS; or narrowly, & therefore somewhat ambiguously, meaning merely no UKMIS briefing. https://twitter.com/tomtugendhat/status/1252679936768344070

The 2nd clarification, that no political decision was made, is theoretically consistent with no decision being made at all, the effect of which being that the UK did not take part. Could such an absence of decision in itself be described as a politically-conscious omission?

Probably not, if the 3rd clarification holds, namely that an invitation was not received in time. If so, however, it would be good to know precisely how & why this occurred, & why any processes in place to guard against this sort of occurrence apparently failed on this occasion.

Overall, this clarification letter is consistent with at least 2 explanations: McDonald was simply embarrassingly confused on the facts; or that the letter artfully squares his committee evidence with ministerial views about what happened/how to talk about what happened.