Because nobody explicitly filed a complaint with the PyCon organizers.
I believe the role they've attempted to take is arbitrator, not police officer or enforcement authority. In short, they don't go looking for infractions, but instead deal with them when someone feels wronged.
And they handle themselves extremely professionally from everything I've seen.
Full disclosure, I previously helped organize PyCon, but haven't been actively involved in a few years.
Disclaimer: My opinions are my own and I do not speak for anyone else or any organization in the Python world.