The problem is proving it was a lie and not a change of circumstances/opportunities during the operation (which doesn't make it right either, but at least dismisses the disingenuous intent).

So your attribution to my thinking is pretty unwelcome. I don't think it was ok, I don't think either it makes Putin's perspective more reasonable or acceptable.

Putin's track record is way worse than that: multiple military or mercenary invasions, journalists, activists and politicians murders, multiple meddling with foreign elections.

This does not diminish the defence fundamentals of NATO. Putin's strategy only reinforced NATO making sense for its own members and for candidates. He could have acted differently, and favour democratic changes rather than making himself a defence to autocratic regimes, both at home and abroad.