There was a lot of speculation during WrestleMania 31 that Brock Lesnar did a “blade job” and cut himself open when they did the ring post spot. Several readers sent the following GIF, which appears to show a referee handing a blade off to Roman Reigns, presumably so Reigns could give it to Lesnar when he got back in the ring.
If this is true, it would likely mean Vince McMahon allowed the blade job, something WWE has generally been against for years now.