My wild guess:
1) Business: ok guys we need to remove the 8 char pw limitation
2) Tester: wth I used to type the same but now couldn't login
3) Dev: that's easy, we just attempt login with full input and if cant we try again with first 8 char only

*roll out*

4) Customer: wth I can login with extra junk char
5) Dev: (*oh shit)