Just don't call Whitey Bulger a rat

Kevin Cullen: Whitey Bulger's worst fear is to be called in an informant Cullen: Public record shows he was a rat, but loyalty, above all else, is the Irish code Cullen: Bulger obsessed with being the good bad guy, who helped old ladies with groceries Defense burden: His friends are vile, murdering thugs, and he was in charge, Cullen says