Head coach Noeline Taurua struggled to identify any positives from the humbling loss and said it highlighted plenty of areas individuals needed to work on over the short break ahead of January's Quad Series campaign.
"I don't know if there are positives coming out of that, I'm not too sure, but I've been able to see people out on court and know once again what we need to do," Taurua said.
"It wasn't consistent in terms of delivery or the final execution of putting the shots through, so close yet so far."
Langman said she was disappointed her side was unable to finish the promising campaign on a high.
"When you pull on the black dress, the expectation is to put out a performance that we're proud of and I think if you were to go around to each player tonight they would be pretty disappointed with what was out there," Langman said.
"I think we can be toe-to-toe with them I just think it was execution tonight and our decision making we were caught two steps behind."
The Silver Ferns were largely on the back foot throughout the lively and physical match with miscommunications and a lack of connection between players gifting the Diamonds plenty of ball.
As warned by Australian coach Lisa Alexander, the Diamonds hit the court with stunning pace in the opening quarter of the transtasman clash while the Ferns were left scrambling.
Sharpshooter Maria Folau, who netted a career-best 40 from 41 goals in test three, struggled to produce a solid performance while Te-Paea Selby-Rickit became increasingly hesitant under the hoop with the pressure from in-form Australian defenders Jo Weston and Courtney Bruce.
Young shooters Maia Wilson and Aliyah Dunn were given opportunities in the circle, however, it seemed not one of the Ferns' shooters could find their form with well below average percentages.
Similarly, the Ferns' defence unit performed far from their best with vice-captain Katrina Grant benched in the second quarter.
Sulu Fitzpatrick was given the nod at goal keep as Jane Watson moved into goal defence, but the changes didn't make much of an impact as the Diamonds stormed ahead.
The Silver Ferns managed to hold some ground in the final quarter as things started to settle but a more consistent Australia held the edge.
The Ferns only have one shot at redemption over the Diamonds in January's Quad Series before the Netball World Cup in July.
