Am I being too judgy?

I just went to a funeral for my nephew last week. He was 14 and passed away after having a really bad seizure. My brother already lost his wife over 10 years ago and never really moved on. When I went to the funeral.... I just feel like my brother was showing proper funeral etiquette at his own son's funeral. He was drinking a LOT and then our mom was having to help him because he was throwing up in the toilet after the ceremony because of how much he was drinking. Then after the funeral he went out to drink more. I found it all inappropriate at his own son's funeral. I told my mom and she said when you lose a child it feels like uour life is over and I'm being judgemental for shaming my brother on how he's trying to get through it. I just don't know anyone who drinks at a funeral.