I'm continuing to follow this thread....
Lets summarise some discussions :-
* The ATC controller in his "interviews" clearly states he was not given altitude reports when requested - the CVR totally agrees with this.
* He must not have had altitude info on the equipment therefore - so it was NOT a PAR/GCA - BUT have the Russians actually confirmed this was the case?
* As it appears it was NOT a PAR then why on earth did the controller more than once say "on path on slope" when he clearly had absolutely no clue (without altitude info) this was the case?
* Furthermore, why did he call "horizon"? As far as he was concerned it was a normal NDB approach to DH. What prompted him to call horizon ? Did he or a colleague actually catch sight of the aircraft (or its lights) through the fog, low down about to impact? If so, why not mention this in the interview?
* I concur, the theory that the PF saw something on the ground to cause them to descend below DH fits very well with the outcome. It does however seem inconceivable that given the tension in the cockpit there is nothing on the CVR to validate this. A call of "look! there it is ", "OK I've got lights " or "there you are" or such like would surely have been made ??
They descended below DH too far for a GA to save them from impact with the tree - Why? We will never fully know.