I don't think it's been shot down by anyone. Imagine the furore if a country had knowingly shot down a passenger plane and had not come forward with this evidence by now.
What do we "know" really?
The comms were deliberately shut down.
The plane was piloted on a specific course using waypoints.
The flight continued for up to 8? Hours.
The satellite pings can be plotted on two paths but cannot be narrowed down to which path specifically.
Each of those two paths throws up differing conclusions. The SW path is a likely suicide, ditched in the sea. The NW path intention to land the plane somewhere for unknown purposes.