That all can be pretty convincing, I admit. But there is something that is more convincing in investigating crimes and that is a motive. In other words, in most times the one who did it - is the one who gains the most from it. What did rebels gain from it? A chance to get hit by US and NATO armies I'd say, a very very bad motive. What did Ukraine gain from it? A whole world support and a whole world hate to the rebels. That's something substantial.
Now, from this report:
1) These objects can be originated from a big ground-to-air rocket. This rockets do not hit the targets directly, rather they explode when they approach it and hit it with multiple pieces. Ukraine had, has and will have such rockets. Rebels presumably had it.
2) From a machine gun from a plane or from air-to-air rocket (Р-27, Р-73) from a plane. Russians provided radar data of a few jets registered at the time of hit and on the plane's altitude (may be fake, who knows). Ukraine had and has such jet planes. Rebels didn't and don't have it.
So, basically 1) could be done by both Ukraine and Rebels (the version that they wanted to hit a military jet and hit a civil plane by mistake). 2) can be done only by Ukraine.
Now, the one point against 1). This rocket from the "Buk" is kinda hard to not notice it. Here's an articale about it containing the video of firing rockets from this anti-air-complex "Buk":
http://sergeytsarkov.livejournal.com/36062.html. As can be seen here this is a hell of a noticeable rocket. When it hits an air plane as big as 777 it will be is a triple-hell of a noticeable event. So, why not anyone saw it? Why not anyone of hundreds of satellites registered it? The trace of the hit will be floating on that altitude for quite some time. But, no one saw anything, even though the weather was pretty clear. And, it may be believable in case of an open ocean thousands miles from land. But, not to notice it in the middle of the place where a civil war is going? There is a lot of villages at that place at least someone had to see something.
So, my point is that it is not that clear who actual hit that plane.