I ran a meeting once where a significant consensus decision was made after lengthy discussion of several alternatives.

The result surprised and disappointed me, so I checked with everyone individually later, away from the meeting, to find nobody in the group wanted the option they voted for, they just voted for what they thought everyone else wanted. Which turned out to be wrong. It wasn't even a compromise, it was just incorrect belief from misinterpreting everyone else's sentiment.

The least popular option prevailed, with unanimous consensus, and nobody knew it was unpopular until I checked after.