Earlier quoted context omitted.
Who is this they?
This study [0] concluded that reduced duty hours for surgical residents actually had no significant difference in patient outcomes. [0] http://www.nejm.org/doi/full/10.1056/NEJMoa1515724#t=abstrac...
Neither one of these schedules is really "reduced" compared to any sort of typical level: they're both ~80 hrs/week (and probably more).
From the paper:
"Programs assigned to the flexible-policy (intervention) group were required to adhere to ACGME duty-hour requirements of limiting work to 80 hours per week, 1 day off in 7 days, and on-call duty no more frequently than every third night, but they were granted a waiver by the ACGME to waive four duty-hour requirements (from the 2003 and 2011 reforms) concerning maximum shift length and minimum time off between shifts (to facilitate continuity of care) (Table 1)"