... Although he's admitted being involved in the death of a child...
If a person wants to assume that the confession is 'factual', in other words that he is describing something he actually did, then look and see if what he claims to have done aligns with the evidence.
After saying again and again that he did not even know the child was dead, and believing that the FBI/police were going to kill him after the interview, as he says explicitly, he agrees that, as a sort of plea for mercy, the police can say that he killed the child and he will go along, but he will not say that he raped the child. He says very explicitly the child was a friendly neighbor child and he will not say some things even to get mercy.
So does the evidence point to the child getting killed accidentally, as he reluctantly agrees to say in order to get mercy?
Note that one of the items raised on appeal was the issue of 'gruesome photographs'. There were photographs shown to the jurors that had no practical value as evidence in the case, except that they showed it was not an accidental death. Somebody killed the child and then violated the body with an object, possibly the towel holder in the bathroom. The police report indicates that the first medical opinion was that the 'rape' was actually an attack with an object, made to look like a rape. A police officer was sent specifically to the crime scene to look for the object.
Even if a person is not familiar with false confessions they would have to admit that he did not accidentally kill the child, then accidentally throw the body around in a way that left bloodstains on the walls, then accidentally 'rape' the child with a towel holder or similar object etc.
There is no indication he had the psychological ability to commit an act like that, nor did he have the motive.
Was there anybody who had such hostility toward the child that they could do that? There was. It was not Mr Met. The killing was the rural Christian version of an 'honor killing'. Somebody felt that a Burmese child should not associate nor talk to 'a bad person', to quote one of the roommates. The child was probably warned. Then on the day of the murder one of the roommates, knowing Met was gone, came home early according to the police report, and the child was probably watching tv in the apartment. He probably tried to 'educate' her that she should not associate with 'bad' people. She probably responded as she would have to a family member, not understanding that she was dealing with a tribal mentality. He felt it was an honor issue, that she was threatening some essential element of their society. Once things had gone to the point where there was a dead body, what was done? Not something that would be familiar to most Americans, but something many Burmese will recognize.
In the news today
http://frontiermyanmar.net/en/death-sentence-upheld-for-myanmar-pair-in-koh-tao-case
previously
http://www.telegraph.co.uk/news/worldnews/asia/thailand/12100567/Thai-police-respond-to-scathing-criticism-from-sister-of-Koh-Tao-murder-victim.html
A few weeks ago
https://www.irinnews.org/feature/2016/12/22/myanmar-says-rohingya-rape-and-abuse-allegations-%E2%80%9Cmade-%E2%80%9D-despite-mounting
note
http://www.thedailybeast.com/articles/2016/06/20/trump-campaign-manager-s-firm-turned-blind-eye-to-burma-rapes.html
2016 although ethnicity is not mentioned, it probably was a factor
http://www.khaosodenglish.com/news/crimecourtscalamity/2016/03/28/1459161982/
2014, the year Met was convicted
http://www.abc.net.au/news/2014-07-21/false-rape-claim-sparked-myanmar-riots/5610300
and
http://www.aljazeera.com/news/2015/10/false-rape-allegation-sparked-violence-myanmar-151027125322964.html
resolved by Burmese govt
http://www.abc.net.au/news/2015-03-21/five-convicted-for-fake-rape-claim-that-sparked-myanmar-riot/6338464
2013 and 2012
http://www.bbc.com/news/world-asia-18395788
earlier
http://www.omct.org/violence-against-women/urgent-interventions/myanmar/2004/04/d16844/
When two societies meet there is often a clash and very often one stage of the 'melting pot' clash is rape accusations, both real and false. In some places in the United States you can still find people who defend the abuse of Native Americans on the grounds that 'Natives raped women'.
If you look into the history of Burmese clashes it might be roughly comparable to U.S. ethnic tensions 150 years ago. Considering the ethnicities of the people involved, their respective educations as well as the evidence in the case it is very unlikely Met was involved in the murder. As no proper investigation has yet been done, and much of the evidence in the case is 'unexamined', to be polite, it would not be suitable to make accusations, but there is enough evidence to provide a general notion of where the case might go if properly investigated.
http://i63.tinypic.com/311lx50.jpg
http://i65.tinypic.com/lfigm.jpg
http://i67.tinypic.com/28tgz9f.jpg
http://i68.tinypic.com/2i7ogj.jpg
http://i63.tinypic.com/55l1tc.jpg
http://i63.tinypic.com/2wps3ef.jpg
added
Here is a video showing treatment of people of Met's ethnic group by police where he came from. It shows that his concern for what the police intentions might be were not an abstraction.
https://www.youtube.com/watch?v=guROoUM8_24
Note too, the only dna found at the crime scene belonged to one of the roommates
"But in several places in the basement where forensic analysts collected DNA swabs, the child wasn't the only DNA profile present, Grundy said. Most samples were too faint to tell who they might belong to, save one: a DNA sample collected from the west wall of the basement."
"There, Grundy said, experts were able to exclude everyone in the home as being possible contributors — including the defendant — except for roommate Ku Nu. Prosecutors said Ku Nu likely left traces of his DNA when he chewed, and spit, a South Asian tobacco-like substance called betel nut around the home. Ku Nu also lived in the basement before Met moved in less than a month before the murder."
http://archive.sltrib.com/story.php?ref=/sltrib/news/57399926-78/met-hser-moo-ner.html.csp