Notice the cut error. Got it out of a ATM yesterday.
I'm not sure why people are assuming that because a note is cut that it is an error?
I can tell you that I know for a fact that there are brickers and some collectors that I know mark bills differently so that when they get the note again they don't have to bother checking it since it has already passed through their hands..this includes everything from using markers, highlighters, xacto knives, hole punches, stamps, and yes even cutting corners as ways they identify notes that they have handled in the past..
It may not be the best way to do it but it is done.
When I was in Toronto, Mississauga, and Kitchener/Waterloo I have come across numerous notes with the BTT and BTU prefixes that were marked and obviously because at one point they were being searched for the double denomination paper..if you really start to pay attention it will happen more often in areas where brickers are searching and returning large amounts of cash back to their banks.
I'm sure others have come across this as well