Farah couldn't run that fast. He had a great kick and finish but that's all. He doesn't have that pace and never had. Mo progression is also suspicious as hell while Bekele was in his prime in a natural age for an athlete.
The thing is that I don't think Bekele can run sub 26:50 or sub 27 now, but he is still able to get within 2 seconds of the marathon record. If he had that explosiveness of his young years he would have beaten the record.