Hackett was encouraged by Kop boss Rafa Benitez admitting it should not have been a penalty.
And he praised McLeish for not directing his anger at Peter Walton. Hackett added: "Both managers were very clear in their views and said it wasn't a penalty.
"Managers are working very hard to cut this out and I know they abhor this type of behaviour.
"Ultimately, it's down to players not to commit acts of simulation.
"It is difficult and sometimes the speed and quality of the player and the way they juggle the ball catches referees out."