Sure I could have found all of the references easily. That's one of the reasons I still prefer Java over a dynamic language- my IDE can tell me instantly (option key + F7) where a particular object is used in the entire codebase. I just wasn't careful enough, because hey, what could possibly go wrong- it's a stupid boolean, right?
Could you check all the references where that b variable was used prior to changing the code?
There likely to be just one or two such places.