A little boy is missing and his biological mother has blamed his foster parents for not keeping a proper eye on him.

Sounds a bit outrageous, doesn’t it? It’s quite a claim – and it was made last night, when the mother of William Tyrrell, Karlie Tyrrell, 29, spoke to Channel 7’s Sunday Night.

In the interview, Karlie, clearly distraught, says, “I don’t want to blame the carers, but yeah, they were responsible for looking after him, and they failed.”

Sounds a bit rich, coming from someone who wasn’t even responsible enough to keep the children she gave birth to – right? Pretty ungrateful. Well, that’s according to the social media backlash after the interview aired.

Karlie Tyrrell: ‘I don’t want to blame the carers, but yeah, they were responsible for looking after him and they failed’. #SN7: https://t.co/KKdsYFVgcx pic.twitter.com/OpTVcVRjNY

— Sunday Night (@sundaynighton7) March 4, 2018

If you were doing your job as a parent, it wouldn’t of been someone else’s responsibility to look after YOUR son. Kids aren’t removed from parents care for no reason at all, twice! Why are we pretty much praising people like this with air time and ????????

— Jamie (@theJ83) March 4, 2018

The story of the darling boy with the mega-watt smile is familiar to most Australians. Little William vanished from his foster-grandmother’s home in Kendall, on the NSW Coast, in September 2014.

His parents remained anonymous, but issued desperate pleas for his return. It was then revealed in 2017 that their anonymity was because William had been in foster care, after being removed from his biological mother, Karlie.

It was a decision made for the good of the investigation. But if anything is apparent from last night’s interview, it’s that the process robbed Karlie of a voice. It denied her a chance to plead for her son’s life, and to speak publicly about him.

Could you imagine being forced suffer in silence for years like that?

So what does Karlie do when she’s given a chance to talk on national television? She explains herself. She tells us that she met the father of her four children when she was just 19 years old.

That she tested positive to marijuana in a drug test, and so her eldest daughter was removed from her care. And that eventually, she was forced to surrender William to the same foster family when he was just nine months old.

Karlie is angry. She’s traumatised. And that anger and trauma hasn’t cooled with the passing years; in fact, it’s increased with every moment.

What Karlie desperately needs is answers. She's had time to think and re-think about the events that led to William's disappearance. She's been wondering, as any parent would, what if, what if, what if?

What if William's foster mother hadn't gone in to make a cup of tea? What if the foster father hadn't been out? 

That came out in the interview as, "I don't want to blame the carers but yeah, they were responsible for looking after him, and they failed."

What if the police had paid more attention to where William was in those first few hours instead of coming to me? What if they'd worked out earlier someone had taken him and he wasn't lost?

That came out as, "Police were knocking on the door asking where William was. I was in shock. William’s not even in my care. I don’t know why you’re coming to ask me. Their police skills were not very high standards."

Listen to The Quicky debrief on the truth about William Tyrrell's parents, and what happened after the three-year-old's disappearance. Post continues below.

It sounds shocking, and the accusations against the foster parents have made headlines today. But if we listen carefully to the interview as a whole, more than anyone else, Karlie's blaming herself.

"It didn't matter what I did I just was never good enough."

"I pretty much don't know where else to turn now."

"I felt like I was the worst mum in the world"

"It's the worst. I'd rather die."

"I just made bad choices."

These are not the words of a mother who is genuinely blaming anyone else for her son's disappearance, other than herself.

Karlie holds back sobs for most of the interview. She is there to beg for her son's life, and answers. The whole point of the interview is to show whoever has information on William's location that he has a mum who loves him.

Sobbing, Karlie implores, "Just let him home come home. He hasn’t even met his little brother yet. That’s not fair, it’s just not fair."

Karlie knows it's not the foster family's fault. She knows the police have done everything they could, and continue to do so. She knows that William could have gone missing on anyone's watch. But he didn't. And so she's thinking what every mother would:

He went missing when I was not there to protect him.

What if I had been there? What if I had stayed? What if I'd gotten clean? What if I had done everything differently?

We don't need to blame Karlie Tyrrell for her decisions, and accuse her of being an insufficient mother. She's doing a good enough job of blaming herself.