But Hank has always been a by the book guy. Law enforcement, especially DEA, can come up with all the bull they want. No question about that. But to see Heisenberg consume Hank to the point of breaking bad (stealing evidence which won't be admissible in a court of Law. i.e. Leaves of Grass, illegally using the tracker on Walt with evidence he can't present, etc.) has been a great transition. , even Marie wants Walt dead, not in prison, but dead.
The point I think I see in season 5b is that Walt is corrupting everyone morally and not just their environments. They will use any means possible to take down this monster even if it means breaking the law.