Temp and hermies

Friend has hermies from stable strains, same ones I grow with no problem. I’ve identified several reasons I thought he was getting them; light leaks and screwed up light schedules from not using a timer but he still got them. Now I’ve learned his lights off temps are 59 on 79 and thinking that’s got to be it but I’ve never grown with that much of a diff. Could that Cause it?

Anything that stresses the plant can cause it, so yes to wide temperature swings, 59 is cold