“The world got to witness possibly the greatest choke in Olympic history a couple of nights ago,” Campbell told Australia’s Seven Network.

WATCH: golden moments on Day 8 at the Rio Olympics

Australians are also seeking answers after their expensively funded swimmers struggled to redeem themselves after a disastrous showing in London four years ago.

Headed by a new coach and bolstered by rising stars, the team was predicted to win up to 11 gold medals.

But by the end of swimming events they came away with only three golds – well below the mighty US’s 16 and even fewer than Michael Phelps, who bagged another five himself.

The Australian public could be forgiven for saying, “well, can we have our money back then?”, Brisbane’s Courier Mail bristled on Sunday.

“The taxpayer contributed just under A$40 million (US$30 million) to fund the Australian swimming programme for the past four years, and they expect a certain return for their investment.”

The Australian newspaper said of Campbell’s meltdown: “The swimming team’s Olympic campaign began with great promise, with two gold medals on the opening day, but unravelled in a race that produced the greatest shock in the pool this week.”

WATCH: relive the action involving Hong Kong athletes on Day 8 at the Rio Olympics

The older of the two Campbell sisters competing in Rio hinted at a possible injury but said now was not the time to talk about it.

“I’m not here to make excuses. Everyone has injuries and setbacks and I’m not about to put anything in print just now,” she said.

“I want my results to stand for themselves and I want to be able to stand and take responsibility for my actions. There may be a few things coming out a little bit later but that is absolutely not relevant at the moment.”

Campbell said it had been a tough week in the pool, where Australia’s wait for an individual women’s gold continued unsatisfied despite 4x100m freestyle success.

While Mack Horton and Kyle Chalmers won 400m and 100m freestyle golds respectively, the women failed to end a drought that has now extended to eight years.

“It’s been a tough week, there is no denying,” said Campbell, after anchoring the Australian women to a final silver medal in the 4x100m medley relay with a last leg that pipped Denmark by just 0.01 of a second.

“But I’m very proud of that swim. I executed exactly how I was supposed to do it two nights ago and came away with a very different result.”

Campbell said the 50m freestyle was a lottery and it just had not been her week, with her number not coming up, even though she had swum faster in Adelaide in April.

Emma McKeon was Australia’s most successful swimmer in Rio, walking away with a relay gold, two silvers and a bronze while the world champions and big guns like Cameron McEvoy failed to fire.

“I probably wasn’t expecting to come away with four,” McKeon said. “Now that it’s over, it’s all a bit surreal. I feel like I don’t know what I’m supposed to feel. Emotions are confused.”

Like Campbell, McEvoy admitted he succumbed to the pressure.

Head coach Jacco Verhaeren was more blunt, saying McEvoy had been gripped by “stage fright”.

Richard Keegan, assistant professor in sports psychology at the University of Canberra, said the pressure Olympic athletes experience can leave even physically fresh competitors mentally fatigued.

“If one’s entire career and life’s work is going to be defined in the next few moments, that’s pressure,” Keegan said

“It is a long-established fact that pressure can make people underperform – whether it be choking, anxiety or distraction.

“It’s one of the main reasons sport psychology was started.

“Even in simple lab settings you can see increases in heart rate, muscle tension, sweat just when people are performing in front of a crowd.”

Reuters, Agence France-Presse