I figured it out pretty quick, but one thing confused me: it counted the lockers from right to left, instead of left to right, so I clicked the wrong one the first time. I'm used to lockers going from left to right, or well. Downward, back to the top one to the left downward again, so when I failed because I hit B1 instead of B12 it was minorly annoying. Still got a bit of fun dialogue out of it.
Viewing post in What did you think of the lockerroom puzzle?
Yep, that was the main twist. The tiny hint is the circle arrow symbol on the key tag, but it was not a hint that was obvious. I think most players thought like you and possibly felt that the direction was not intuitive. But hey, that's one of the thing the wrestling federation did to make them more confusing to people who have not been invited to the lockerroom. Don't want them stealing all your jocks, after all! :)