We know the ending don't we? The bomb doesn't succeed as planned [outside instead of inside, the moved briefcase, the strong table, not including the second packet of explosive, yadda yadda yadda]. And, most of the plotters are caught and executed, some after sham trial, some without even that.
It reminds me of when my stepsisters got beyond mad at me when I "revealed" that Pompey would get killed upon arrival in Egypt when we watched "Rome".
It's history. How much of it can you fudge anyway?