In "Hammer Time," Sipowicz, on his first day back after surgery on his prostate, wets himself while interrogating someone. He gets into the restroom as fast as he can, but Medavoy sees what happened. Medavoy goes into the restroom, where Sipowicz is hiding in a stall, and (without mentioning what happened) says that he has a spare pair of pants in his locker Sipowicz can use. Sipowicz, who was often quite a Jerk Ass (especially to Medavoy), takes the pants and sincerely thanks him.
Seeing Meadavoy finally succeed both romantically and in starting a new career towards the end of season 12, and being able to retire from the NYPD happily, rather than in disgrace (as he was afraid would happen earlier in the same season).