According to PWInsider.com, Brock Lesnar blew up after the Extreme Rules pay-per-view this past Sunday night, and began tearing apart a dressing room.
Lesnar apparently felt double crossed by the promo that John Cena cut at the end of the show. The original plan was for Cena to be hurt so badly that he would have to have been carried out of the building, allowing Lesnar to claim that the loss was a fluke.
The report goes on to note that the angle on RAW last night was the original plan all along to remove Lesnar from TV, since his current deal only calls for a minimum of two dates per month. You can check out the full report by clicking here.