Does Dad have a say in baby matters?

Mom started feeding baby infant cereal at age 10wks. Dad didn't think much of it, because he's clueless about these kinds of things. Dad, wanting to learn more about the subject found http://babyparenting.about.com/od/startingsolids/a/startingsolids.htm and told Mom: "I'm not one to tell a mom what decisions to make with her baby, but I did read an article that said a baby shouldn't be fed solid food until 4 months and X, Y, Z (see article). Mom said she was fed solid food by her mom at 2 weeks. Apparently feeling threatened, Mom got insanely mad at Dad, yelling insults, threatening to leave the marriage, etc. Wtf? Dad really wants to know what the right thing to do is next time... shut up and trust Mom regardless, or continue to voice opinions and concerns knowing that he's going to get torn a new one.