Malthouse said the final margin in the match could have been greater had the reigning premier better capitalised when it gained momentum in the match.
"Just when we looked like we had a five-goal or six-goal lead, all of a sudden it's three goals, because we just didn't put them away the way we should have," Malthouse said.
"We tried to do a few things that are not anywhere near what we expect of our playing group.
"And I'm talking about kicks that were not to the right position - we were too clever - kicks that weren't ideally where we needed it or how we wanted it."
Malthouse refused to put the errors down to overconfidence, suggesting the Magpies simply needed to make better decisions when under pressure.
"It's got nothing to do with selfish, it's just not good football," he said.
The premiership coach pointed to an example of Jarryd Blair, who was impressive with five goals, handballing to Dane Swan when the star midfielder "had three blokes hanging off him".
"(Blair's handball) should have been kicked or handpassed to someone else," Malthouse said.
"That's not thinking through the situation. It's just not thinking about the alternatives.
"If that player was covered, there should have been someone else in a better position. So that player has got to think through it a bit quicker."
Malthouse suggested some Collingwood players might be starting to flatten after reaching a high level of performance early in the season, forecasting changes to the side's structure to help share the workload.
"Some of these blokes have been up for a few weeks already," he said.
"We've scheduled it in to have certain players play good football in April, and they've done it pretty hard through February and March.
"So this is a time when you analyse players that are starting to tire a little bit and start to throw the side around so that other players can take a bit of the pressure off."
One change Malthouse expects to see is recruit Andrew Krakouer spending more time in the middle of the ground.
Krakouer was pivotal as the Magpies kicked away in the second term, booting two opportunist goals, but finished the match with just nine disposals.
"He'll get better as he gets used to AFL football again," Malthouse said. "We saw enough of him last year, how good he was in Western Australia.
"When he gets some miles in the legs and a few games under the belt he'll work through the midfield, because he's got that touch in there as well."
