Advice for tent growing is to make sure the are no light leaks at all. Any light leaks, even minor ones, will spoil the grow and disturb the plants from flowering (so it is written anyway).
So how do outdoor plants deal with streetlights, moonlight, porch lights, etc? How does any cannabis plant flower outside in a civilized area? Not trying to be a wise guy, just curious.
Thanks.
Oh go ahead and be a wise azz… 
Your question is good outdoor grows can take full moon light and not get messed up. I agree the caution is over stated…
I grow outdoors my living room lights shine on my plants my bathroom light shines on my plants. I try to limit exposure time and intensity as much as possible. I found a couple seeds on one of my plants but no signs of a Hermie. If theres a light on all the time thats close enough and bright enough I guess it could cause a plant to hermie. The moon and stars dont really put out enough light to hurt anything. Dim lights through curtains don’t either
I grew outdoors last summer. We have security lighting that triggers on movement as well as the surrounding neighbors. Also street lights. No hermies.