Did he feed her the formula straight away? It’s probably because he overfed her or as Sharnee mentioned he didn’t pace her and she might have swallowed a lot of air. Also did he prepare the formula correctly? I’d say test he again with the formula but I would advise you start small and introduce it to her first by giving her an ounce every day so it won’t be a shock to her tummy next time she needs to have a full bottle.
I've been told that you can't overfeed a baby. Not sure how true it is though. I will say, if she's only had the Kendamil once before, it could be her not agreeing with it properly as it's whole cows milk and can be a lot for them. She may have had some trapped wind that didn't come out & that caused her to be sick. That's happened a couple of times with our LG, she usually does 3 burps and if she doesn't, she will more than likely throw up 🤦🏻♀️🤷🏻♀️
Did he pace feed her?