#3 Paul Heyman costs Brock Lesnar the match
Paul Heyman is the best manager/advocate in the WWE. He has been alongside 'The Beast Incarnate' Brock Lesnar since his initial days in 2002. The wrestler has taken down opponents inside the ring while his advocate has taken down his opponents on the mic.
We have seen 'The Humble Advocate' take down his current client's opponents in more ways than one, but he has also betrayed his clients in the past. We did see him betray CM Punk during a championship match, and what transpired was a wonderful storyline.
As Brock Lesnar is rumored to be off to UFC soon, the WWE could start that storyline where Paul Heyman costs Brock Lesnar the match, and this helps Lesnar take some time off before preparing for his match at UFC. This also sets up a storyline for his return, and there would be a great pop when he returns after his match in UFC.