Discussion from Facebook
Someone asked about the case of a double ron, where one player committed a chombo (such as invalid hand). It was mentioned, that the hand awards the valid hand the points; and the game continues on, without invoking chombo. Apparently, a source is pointed here: http://ja.wikipedia.org/wiki/麻雀の反則行為 KyuuAA (Talk:キュウ) 11:06, 24 May 2015 (UTC)
There's something about Scott and Jenn talking about a double ron with a chombo followed by a second player who chose not to reveal given that the chombo was already declared. That was considered kosher as some (but not all) allow false ron calls that weren't revealed to be simple dead hands, thus enforcing the chombo.
As for chombo vs legit scoring hand, the chombo is ignored. Double chombo with no winning hand taxes both people with their shares owed to each other canceling out. Senechal (talk) 17:50, 26 May 2015 (UTC)