"decertified" and "rusting hunk of twisted metal at the bottom of the ocean" are two different things. Apparently the US government agrees, people like Victoria Nuland made a point to express their satisfaction that it's the latter now.
Depends what you mean by "ended", one of those is permanent.
I'm not saying being happy about it is proof they did it, I'm saying that it indicates that they are aware of a difference, and that it indirectly bolsters the argument for a motive.
I really doubt any of these points would be in dispute if all this circumstantial evidence was pointing at Russia.
