I don't have the study, but it's so ingrained it's literally a meme. The idea of a "white knight" is based off the idea that men defend women without actually having idea whats going on. The "how can she slap" meme came from a show where a woman slapped a guy when she wasnt allowed to, and it shocked him so he slapped her back. Instantly every dude in the crowd got up and started beating his ass, even though she literally assaulted him outside of the rules of the show. There's also the trope of guys doing dumb stuff "because love" or to show off to women.
I'm didn't read enough to follow his point nor yours outside of that, but there is definitely a point to be made that men do tend to defend women from strangers, just not from friends.