SAS Australia, season 3: Boyd Cordner, Cassie Sainsbury and Princess Klim say goodbye

And this is the lure of SAS Australia: humans.

Two season three recruits - polar opposites, convicted cocaine smuggler Cassie Sainsbury and much-vaunted Balinese princess Lindy Klim - made voluntary withdrawals. More on that later.

The third recruit to go this episode was the medically withdrawn former NRL player Boyd Cordner.

In complete contrast to the seemingly meek withdrawal of former AFL Brownlow medallist Jason Akermanis a day earlier, Cordner made an emotional exit.

Just as he suggested his body failed him during his NRL career, it broke down again on day two in Jordan. But not before he laid his heart bare.

Cordner tore a pectoral muscle leaping from a pier onto a rope dangling from a hovering helicopter.

It was a challenge that didn't end well for most of the recruits but Cordner suffered worst.

As he received the commiserations of the SASers, from boss man Ant to the medico, he emotionally recalled losing his mum to breast cancer as a four-year-old.

Heart strings tugged all over the place.

As did a few for Sainsbury too, who just could not get over the psychological damage she suffered in a Columbian jail.

The"submerged pipeline test" was a bridge too far for her, too close for her memories of jail in Columbia to allow her to conquer.

"It is probably one of the first times in a long time that I feel proud of myself in the sense of facing everything I didn't ever want to see again."

"When I leave the SAS course 'Cocaine Cassie' dies there. That's it. She doesn't follow me around anymore."

She mightn't but certain media organisations will.

The total non-surprise of the episode was Princess Klim drawing a line under her experience.

After admitting she enjoyed a podcast before bedtime, as well as some whale noises, In the most "no sh-t Sherlock" moment of reality TV, she admitted she "was not built to be a soldier".

The most heart-stoppingly surprising moment was Thai Cave rescuer Dr Craig Challen messing up the 30m pipeline test.

Mere mortals made the rookie mistake of diving face first into the hideous brown sludge but surely not the man who helped pull off the save of the century and rescue 13 trapped boys in 2018 ...

Well, that's what pressure does.

Hurrah for the SASers who saved his backside and then ever-so gently attempted to tear a strip off it.

Instead they teased out more details of the humble doctor's feats that kept the world so enthralled those years ago. And paid him - as well as Cordner and Sainsbury - the respect they deserved.

SAS Australia continues 7.30pm Wednesday on Channel 7 and 7plus