The Magpies fought hard, but from the middle of the second term couldn't go with the Saints, who kicked 12 of the next 14 goals.
But Malthouse said St Kilda's pressure was to blame for the Magpies skill errors, which included kicking a wasteful 9.18 – six more scoring shots than the extraordinarily accurate 17.4 of the Saints.
"I don't think we were missing personnel, I think probably what happened ... well, number one is congratulations to St Kilda, I thought they were very very good," he said.
"I think that (inaccuracy) is more the St Kilda pressure. Jack Anthony has rarely missed all year – maybe the pressure got to him, he missed a couple of shots for goal that I would have expected and so would Jack.
"Again, it's a lesson in life – take nothing for granted. Jack must go back, kick a goal. He'll learn."
The proper use of practice time was something Malthouse said would have to improve at the club next year.
"It's very hard for young players at times, when they get on the end of training, and they have their own 10 minutes at the end, and 10 generally means backward kicks, sideways kicks and up-over kicks they can do.
"But perfect practice makes perfect, so it's a great lesson for Jack – take nothing for granted. Use the 10 minutes at the end of training to kick goals every week."
Malthouse's post-match address to the players was captured on national TV, and he is believed to have touched on the need to realise that reaching the second week of the finals was no reason to pat themselves on the back, and to use the loss as a catalyst to drive them forward next season.
But he refused to elaborate on the contents in his media conference.
"That's why we lock the doors, otherwise we'd open it to everyone, wouldn't we?
"That's why we close the door. It's not unusual for the coach to address the group after a last game."
