I use two...250 Red Kill Lights one on the rifle scope and one for scanning...I have yet to have a red fox run away... Could be your dropping your light or turning to the side... The red lens is your shield... You have to keep it in front of you. You move to the side or lower to much at an angle.. That can make them run away. I keep both of my lights on so I'm actually hitting them with 2 each red 250 kill lights illumination and they aren't running away..

To make a long story short....as soon as you see eyes... You just keep that red light in front of you and don't start to scan other places for eyes...Now you can shut your scanning light off as soon as you see a fox but makes sure you stay behind your rifle rest and that 250 light best be on before you shut the other one off.. So now your behind the scope light and you just shoot them...
I have had coyotes come right up to me this year.. Again..you have to keep that light out in front of you.. No scanning to the left or right if the predator is in front of you...All these years I thought the Pa coyote was light shy.. The problem was there was not enough light in front of me... The Red 250 Kill Light fills that void now...
IMO It could be not the Red 250 light scaring them away but hunters scanning technique once they are in front of you..