Regardless of who exactly fired the missile that killed 298 innocent people, and who issued the order to do so, the Donetsk pseudo-state is a wholly-owned Kremlin subsidiary, with its top-three power ministries all in the hands of Russian citizens who are longtime creatures of Moscows special services. The only law in the DNR is Putins, as exercised through GRU channels. As such, it is difficult to imagine anyone undertaking any important decision there without Kremlin approval and the go-ahead of Russian intelligence.
http://20committee.com/2014/07/19/donetsk-rebels-and-russian-intelligence/