For the hundredth time: MMA is about matchups!
Volkan Oezdemir is a powerful striker, which is why he's dangerous for everyone who's not able to take him down, but vulnerable to every fighter with solid offensive wrestling.
Reyes on the other hand has actually very good defensive wrestling, which usually is something very important, if you're fighting Jon Jones.
Also: Volkan might've landed the more damaging blows, but Reyes still outstruck him, so it's hardly as much of a robbery as people make it out to be, if at all.