Len, the point is what if its foggy at night? Yes we all agree you shouldn't use fog lights at night when its clear, or during the day if its clear for that matter!
But if its night time and proper foggy, then you should use your foglights. Non of the links say you cant use your foglights at night, just that you should only use them when the visibility is very poor.
If your mates had their fog lights on in thick fog, they would not have been pulled for it. I'd hope they would still have been pulled if it was during the day as well, even if its light out rear fogs still dazzle you.