A very humiliating moment, where things feel like they are crashing, a low point. Rock bottom.
Used by Oprah to descibe her "most humilitating experience in my life", when shopping in Hermes for her friend Tina Turner she was turned away by the staff very rudely (as she said it). There are several variations to this story.
The phrase "Crash Moment" refers to situations where a party feels (or actually is) discriminated against, treated with hostility or disdain on the basis of skin color or ethnicity. The term was inspired by the Oscar winning racerelations film "Crash".
I was at an formal event where I was the only Black person in the reception hall, and everyone assumed that I was there to serve, despite that obviously dressed for the occassion. In fact, someone even handed me dirty dishes to take to the kitchen. I realized that I just had a big Crash Moment for me.