The Hammer and Scorecard issue may be a red herring. Dominion's system is porous. Penetrations can be made at numerous levels to switch votes, eliminate votes, etc. "Fraction magic" makes it all possible (see second link).
https://www.youtube.com/watch?v=PhwarD7ihks&t=2815s
https://www.youtube.com/watch?v=Fob-AGgZn44