When asked if the trajectory was still shallowing, FDO answers "Nah, not so much. Seems to have slacked off after LEM jettison. That's where the venting must have been from, the LEM." In actuality, the venting was from a damaged oxygen system on the Service Module; the Lunar Excursion Module was undamaged.
Apollo 19 commander Tom Stafford is seen training in a simulator in a small cameo, but the circa 1974 mustard yellow flight suit he's wearing was not in use at the time of Apollo 13. The footage is from when he was training for the 1975 Apollo-Soyuz mission.