Is it microagression when an atheist rolls his eyes at a Christian?
To answer your question, you must also understand that there is a protected class (oppressed class) and a privileged class (white males in particular). Only victims who are members of the protected class can sue since they are the ones who face microagressions from the privileged class.
In your example the atheist is a member of the protect class and as a victim can sue; the Christian, a member of the privileged class cannot.
Yes, it certainly is.
The way to deal with something like this is to go Alinsky back on the Alinskyites. They’ve created a system for capturing microaggression, so make them play by their own rules and flood the system with reports.