It is rather obvious that whatever evidence is in possession of Turkey will not be handed out. Particularly video evidence would make it blindingly obvious where the cameras surveilling the inside of the consulate have been hidden. This is harder to judge from audio recordings but still at least the rooms and some details could be pinpointed.
So Turkey can make very accurate accusations but they will not be able to present evidence.
As a result of that, I don't see what chance they stand against grandiose denial and fabrication of a story about nominal scapegoats and unfortunate accidents, given the financial interests in this not having happened at all.
Is there any way where, given the lack of presentable evidence, it will not be easy to fabricate opportune denials of anything that may have transpired?