first guy to die in an mma match was a russian. I believe it's still on youtube. This was also due to brain injury caused by something before the fight. Just like the guy in texas. Happens in soccer a lot more than in mma.
One more point. In mma people only fight every couple of months or so. Other sports it can be like 4 games a week. I don't know wether the report takes these factors into account, but it does make sence right?