Etiquette

The Pet Tech is congratulating himself and his team on having successfully resolved something that's been a bugbear for nearly a year now, loudly expressing his amazement at the organisation's lack of communication skills and impressing upon everyone that if his team had known about this problem from the start much unnecessary work could have been avoided.

He's not being particularly obnoxious about it (yet), but this does raise an interesting point of etiquette. Is it considered more polite to:

• appear needlessly quarrelsome now by reminding him that that he and his team were aware of the problem, involved in meetings to deal with it, and advised of the workaround that's been in place for a year; or,
• let him keep going until he does get obnoxious about it, and then forward him the email chain showing he'd been told about it ages ago, particpated in meetings in how best to work around the problem, and then did nothing?