You have to remember that most people don't rationalize every situation in their life. Her feelings are hurt and have been multiple times. She thought she could change a behavior and it hasn't been working even though they 'compromised'.

She didn't turn his home into a security checkpoint either. She knows he smokes pot so you'd expect the pot/pipe/whatever to be in a drawer in a room, but not in the pocket. It wouldn't be hard to notice a pipe either, especially if its a glass pipe.

The fallacy here is the belief that you can change a person when they have no internal motivation to do so, themselves. That's all this comes down to and to be honest it's better to get out of a relationship with someone then constantly be disappointed because you don't approve of something that they do.

You don't need to partake in organizations to dislike something. She isn't so against the drug that she's demanding that he stops using all together. There is probably a reason why she dislikes him smoking during the week that hasn't been disclosed.

This kind of arguing will not help the OP though.