Still, I do believe a lot of people who reported 120 hours back in the day tended to round up. I remember my co-students recalling 120 hour weeks on our surgery clerkship, and they were off by about 30 hours.
Long weeks may have been 120, but I don't think most programs averaged 120 even before 2003. I would guess it was more likely 100. This is based on discussion with my senior residents and subsequent colleagues, as I admittedly trained post-2003 work hour restrictions.
In a night float system, it's very difficult to get to 120, as it would require 17 hour days every day obviously. 4am to 9pm happens, but not daily outside of a program with extremely poor balance.
In q2 call, the 120 hours can occur, so I guess in programs where q2 call was standard 120 happened every week.
In q3 call, it's hard to do, and requires essentially no days off and full post-call days, once again a reality for some, but not the standard across training programs prior to 2003.
I'm not defending the other person's skepticism, but I have been a firsthand witness to many self-proclaimed 120 hour weeks that were actually much less.