Watch the replay. When they come off the final turn, Edris is out wide and Chelimo is in between Farah and Edris. The rule is they have to hold their line from that point out. Edris actually comes in on Chelimo trying to hold him off, which initiates the contact. Chelimo is not at fault here.
To further back up what you say, is there another video clip with a front view perspective out there?