Batman: Arkham Origins

Continuity mistake: When going to the Gotham City Bank, the clock tower bell will begin to ring. Alfred then contacts Batman and says that it's now 12:00 AM and wishes him a merry Christmas. If you look at the clock tower, however, the clock says that it's only 9 o'clock.

Blackgate Prisoner: Jingle Bells...he he he... Batman smells...he he he.
Batman: No.

Question: When Batman and Alfred look at the memory card and come across Slade Wilson, Batman says that Slade's part of a failed experiment. In what way was the experiment a failure considering how efficient a killer Slade is?