There is no reason for us to believe anything the NK have said about this sad incident since day one.
I am surprised that people still visit there as tourists - don't get me wrong I can understand the curiosity but we know it is probably the most brutal stable regime in the world so you have to know you are taking a huge risk to visit.
There is nothing like we would understand to be "due process" or a "rule of law" - you are entirely at the whims of the state's representatives.
+1
North Korea is evil and are responsible for this but going to NK is a bit like a Jew booking a vacation in Nazi Germany.