You're right, Cathy did not make an 'either/or' statement, but she heavily implied that violence was equitable against trans women and TERFs (something that is just completely incorrect)
Trans women are murdered every year. It is legal for doctors to withhold medical care from trans women. This is systematic violence -- NOT akin to a few cherry-picked instances of 'punching TERFs'.
I believe Cathy created a very flawed argument when she cherry-picked instances of violence (much of which wasn't even violence but just graffiti or a tweet) against TERFs but did NOT extend that courtesy to revealing attacks against trans women. Again, attacks against trans women are disproportionately high.
Cathy's argument insinuates that violence comes from both sides, which is just not correct. I encourage you to research hate crimes against marginalized groups. Imagine if your own identity made you a target for murder.