Red flag yes?

[MooningIntoTheAbyss]

This is not for me as I'm still in divorcing hell. But someone I know who told me this story and I think it's a huge red flag but she isn't seeing it.

She started seeing a guy about a year ago. Everything seemed fine so she introduced him to her child. Everything fine and dandy. That was 2 months ago.
Today during a silly bicker type argument over mundane household stuff (he stays with them several nights a week) he seemed to become more rattled then usual.
He ended up yelling at her and called her stupid, but she says he 'spat' the word out with contempt. (Doc was not at home for any of this.)

They have since spoken about the outburst and she aid she wasn't prepared to be in a relationship with someone who spoke to her that way and over reacted that way, after a nasty marriage and a nasty divorce she isn't prepared to go down that road again.
His response was to apologise, say that he shouldn't have gone that far and now he knows the boundaries it won't happen again.

She is swayed by this as she sees some logic in it, I can see what she is seeing but I also see a huge red flag. It shows to me that he thinks the boundaries are much looser then she does. For him the boundary hadn't been breached with this behaviour. I feel that the next time he is annoyed and wound up he isn't going to stop at her boundary cos in the moment it won't occur to him.

Now, I am in e throws of a messy divorce with a very angry, selfish man. So I am slightly concerned that my view point is bias.
What do you think? I will likely show her this thread as I am worried as they talk of moving in together.

[Firstmum24]

Perhaps it was just a turn of phrase? Such a shame though no one in any relationship should have to put up with that behaviour.

[MooningIntoTheAbyss]

she says he has never called her stupid before. Not once in their whole relationship, and he knows how much she dislikes it as a word because it so derogatory. Didn't mean to drip feed that btw!