I mean, exactly what is preventing Hank in Breaking Bad to tell the DEA the whole story after he learns that Walter is Heisenberg? Also, when Marie tells Hank that Walter has paid for Hank's physical therapy, Hank tells that he is ruined. What would happen if Hank just went to DEA and told the whole story, since he knows it now (S05E11)?
Also, does the "confessions" clip Walter made has really a significance? Can't Hank say that it is just a big lie? I mean, I understand that Hank does not enough proof to convict Walt at the time (S05E11) but neither does Walt. I mean Walt doesn't have any "evidence" on that "Hank was a drug kingpin" claim he makes in his "confessions" clip. So, how does that clip have any significance in the purpose of keeping Hank back?
EDIT: If the reason is Hank's (possible) thought: "If DEA learns that Heisenberg was under my nose all this time, and I was not able to see it, everything would be done for me.", how accurate is such a thought? I mean, who thinks of looking to the people closest to them when looking for "such a monster"? Would DEA make such an evaluation on Hank? If they would, how sound would it be? If they wouldn't, what else keeps Hank from telling DEA about Walt?
P.S: Please do not give spoilers from after S05E11.