At one stage in the third quarter, Carlton had fired 22 shots to nine –10.12 to 7.2 – yet led by just 22 points.
"We took a lot of marks in our forward 50 (that) we didn’t capitalise on,"
the Carlton coach said.
"We missed a couple of very easy shots. Sometimes you get paid back at the end, which we didn't but we could've."
Malthouse indicated the Blues' post-match review would focus on their defence.
"I suspect we'll have a close look at easy goals scored against us," he said. "We'd like to think that we squeeze sides to make (them) earn every goal, and they didn’t.
"They’re a good side that will capitalise on any mistake you make, and I thought that probably half their goals were (what) I would label soft because we didn’t put the right pressure on either the source or the exit.
Malthouse said his Blues side was still a work in progress, despite the lofty expectations placed on Carlton by some.
"You’re continually learning," he said.
"Can Kreuzer and Warnock play in the same side? They've got to find the form and the balance, so today was a good step for both boys.
"Can we let a (Justin) Westhoff get behind us and cause some damage? You've got to use the ball differently.
"So there's a lot of work to be done but we're enjoying it and I think we're going in the right direction."
Malthouse insisted there was nothing sinister about Jarrad Waite's substitution at three-quarter time, despite the game still being alive, particularly given Port Adelaide's reputation as fast finishers.
"Someone has to go (off)," he explained. "(We) just wanted to get Troy (Menzel) in. Fresh legs."
The Blues face the Brisbane Lions at the Gabba next Saturday night. The Lions are fresh from causing the upset of the season – a 10-point win over Essendon at Etihad Stadium on Saturday.
"I've said it all along: I think the competition is closing in," Malthouse said.
"Sometimes it's confidence, sometimes it's a player that's out. (Simon) Black has been out of that side and he comes in and he, I know he got subbed out, but he's a leader. (Jonathan) Brown stands up.
"They beat a very good, form side on their home ground … We know we're in for a really tough game."
