Tu-204 has two engines PS-90A. Those engines are equipped with mechanical system that should prevent increasing of rpm if TR is not fully deployed. It is not clear if this system was bad adjusted (on both engines??) or if it doesn't work perfectly. MAK did some tests with RA-64050 to find the answer. I don't know details.
Anyway I suppose that it is not the cause of the accident but it was surely contributing factor.