I was tasked with adding some users to Active Directory today. I did all of this, however, I had a list of 20 users to add. Of this list, it listed 5 users already added.
The list's instructions were basically to just add the users, so I did. There is no way I can get passwords of existing users from AD so for testing purposes I changed these passwords of the existing accounts. Unfortunately, these accounts are in use (don't know how often).
My senior dev said it's fine learn from your mistakes you weren't to know (I did make a similar mistake just days before but that was due to attention to detail and was 100% my fault but I am still doing ok in my job - I'm on probation - as my senior dev always says).
There has been no client impact (yet?). How big a mistake is this?