Milk question

My wife has lived her whole life believing she was lactose intolerant, she can eat hard cheese, yogurt, butter, sour cream etc, but never pure milk milk. At the place I work we use a specific brand of milk called “ mill King “ and this was the first time she was able to have milk in her coffee and not get taken out. I asked a couple of other people and they’ve had the same experience, never being able to tolerate milk until they tried this specific brand. I was curious if anyone had any insight into why or how this happened, I spoke to my chef and he said it have something to with the way the milk is pasteurised, since the milk is pasteurised at low temp it maintains more enzymes that naturally break lactose down.