The "actual innocence" bar is thanks to that piece of shit "supreme justice" Antonin Scalia (and the rest of the not so supreme court) who infamously signed off on a judgement that "evidence of actual innocence is not sufficent for habias relief".

In other words, if you are on death row and your lawyer walks into court with the real killer and he gives all the details that only the killer could know, you still can't get released.

It's insane and sick.