[Roger Kaputnik]

So, what was the motive / reason for shooting I down?

[1rudeboy]

It was an accident. They thought it was a Ukrainian plane.

[annalex]

Here's the key sentence:

"They need to know who has pressed the button on them. They should also know who the orders given for the firing of the missile"

Observe: Bellingcat does not know who shot MH17 down and for what reason. But Bellingcat has evidence of chain of possession of the Buk weapon.

The prevailing theory is that the Russian military loaned the weapon to the separatists (with or without the personnel capable of aiming it properly), who then shot it at the airliner mistaking it for a Ukrainian military plane. The crew of the Buk are identified in the investigation and they should be able to corroborate or controvert this theory.