Andrasz.
I tend to avoid subjective theories as confirmation bias tends to get in the way of open minded analysis, in this case, unless you have any definitive information, that is precisely where everybody, investigators included, stand as of now.
To date, and from the information contained on the links that you kindly supplied, I fail to see either a smoking gun or any statement as to "the probable cause". Perhaps I have missed something ?
Respectfully yours TR