In what edition of the rules, for what system, and what page number of that rulebook would I find your version of these rules in?
They are not forced to believe anything; but they also can't tell a lie was made unless they beat the bluff check with an opposing sense motive.
You might have a point if instead of suggesting the guy I killed had a heart attack, I suggested the paladin killed him and he was made to fully believe that. That's not how persuasion works, even in PvE.