I'm curious about the wording of the petition. If it was anything like the subsequent pro-Prop. 1 direct mail/notification/robocall barrage, then the text of the petition may have been deliberately misleading.
The prop wasn't on the ballot everywhere in the area, and they collected signatures door to door for the petition in areas where it wasn't on the ballot.
Examples of the Prop. 1 campaign: http://www.burntorangereport.com/diary/32038/truthiness-abou...