Ok, here is an example:
Last year at my college class, I taught an escape froma rear grab. A few days later, the young lady was accosted in the parking lot late one night. She used the technique I taught her, dumped the attacker and was able to get away. Went to the police. As it turns out the, Officer she reported to was a friend/student of mine. He found and arrested the guy and told me about it the next day. The following week the young lady told me about the incident, and I knew she was telling me the truth.
Hope that helps clarify.