To me the title sounds like they just mean the missile was made in Russia, which was obvious from the start. (Even if the Ukranians had been responsible, their missiles were still made in Russia!)
What they actually mean is that the missile was transported in from Russia shortly before the shootdown, and the launcher and remaining missiles went back to Russia not long after. But yes, the wording of the title is way too vague.
The way I read it is that it's more than it was made in Russia, that was pretty obvious, the title implies that they were brought from the Russian stockpile rather than the Ukrainian one.
I'm not sure which title you're commenting on, but if it's the current HN title, note that it's been changed. It previously matched the title of the linked article, which is "MH17 missile 'came from Russia', Dutch-led investigators say."
No, because it's never been a point of contention that the missile was fired from within (some part of) Ukrainian territory. What people have been generating noise about is the question of whether the missile came from Russia (before being launched) or from Ukraine's own stockpiles (being as Ukraine did have missiles of a similar make and description, apparently).
It doesn't actually matter whether someone moved the missile a bit outside of Russia to fire it and took it back to Russia after the fact or did it from Russia.
What they actually mean is that the missile was transported in from Russia shortly before the shootdown, and the launcher and remaining missiles went back to Russia not long after. But yes, the wording of the title is way too vague.