The entire world except Russia knew Russia is responsible but when you are the second guy with the most nukes, you get away with impunity. Just the idea of having one or others thinking you have more than one nuke is enough to allow others to look the other way and let you do whatever gay shit that you do
The report did not go into finding out who did it. Both sides own BUKs. It is very difficult to find the truth because all sides are pumping out propaganda. Even the United States is manipulating what we hear for their own political and economic gains. Here an subtle but strong example : http://www.sott.net/article/302911-Sott-Exclusive-Full-unedi...
Only the Russian side has these BUKs. One of the key findings is which specific warhead version was used. The report doesn't spell out who did it, it does however conclude that a BUK missile from the Russian military shot down the plane. That BUK may have been stolen or on holiday in eastern Ukraine.