It's not quite that Holly didn't tuck properly, it's that Holly was being a dick, as usual.
Holly, as is his usual schtick, was grumpy that Brock was getting such a push so, on his on accord, decided to give Brock a rough go of it. When Brock went to pick Holly up for a powerbomb, Holly didn't help Brock lift him by tucking, and instead deadweighted Brock. Normally that'd just make the guy delivering the powerbomb looking weak, but Brock was strong enough get Holly up, but Holly was still stretched straight and so he was vertical, upside down.
Anyone else might've tried to work around it, but, Matt Capotelli or René Duprée, Brock was not. He simply said "Fuck it" and drove Holly straight on his neck. Badass.
To my knowledge Brock suffered no repercussions after this as most felt it was Holly being Holly and, in this case, Holly was unwarranted and got what he deserved back.