Some folks have never seen or experienced true darkness being brought up all there lives in the city and suburban areas.
They tend to panic when this happens...
"Nightfall", by Isaac Asimov
That book alone is a excuse to buy a flashlight or 3.
The thing is, they weren't in full dark. I checked the lunar phase of February 15th, and it was a full moon that night. If they were hiking out under foliage or it might explain why they were having trouble seeing. OTOH, if they didn't keep their cells pointed down trail instead of their faces, their night vision has no chance to develop.
Ironically, I've found you only need about 9 lumens on a moonless night to navigate a trail. Most of our EDC lights will do that. You don't need a 100 lumen battery muncher for on trail night hikes.