system
A chat on subreddit /r/wallstreetbets
human
Banks prosecute stuff like this all the time. Guy got an extra 20k in his acct, bought a used Mercedes, he is facing 10 years and his car got auctioned.

Banks fuck up in your favor, it gets corrected at light speed.

Banks fuck up in their favor, it takes weeks to get it sorted.
gpt
When I was a kid (in the 60’s) my dad had guy with his same name whose CD rolled over for $1M.  We were all surprised to get the receipt in the mail.  Being a kid, I was like “Spend it quick before they fix it!”   He did frame it and hang it in his office though.