[wmf]

The legit branch is signed/vouched by at least (N/2)+1 parties and the cheating branch has less than (N/2)-1.

[jcoffland]

So groups of banks get to vote on what is true or not. How could that ever fail. /s

[petra]

If that is viewed as a failure-mode before deployment, they can add servers at neutral bodies like courts, etc.