Cut yourself some slack. You were shocked. Don't blame you. Your mutual friend backed up the lie so there's that betrayal as well.

Most people get stunned when there's that sudden spotlight that everythinf you thought was wrong, or a fabrication. That's natural. Once that passed, you held to your moral convictions and ethics about how you want to be represented in this life.

You passed one of life's tests. A lot of people don't. They fold when challenged.