I have run into this on a few occasions, but you have to have a very open mind. Sometimes guys change the day, or change the clothes she was wearing, just so she cannot blame him..
A guy name HeadinSouth who is a vet of TJ and mongering even made a post a few years encouraging guys to change some facts, but report on the service and price accurately. His angle was that if the chica accused him, he could say something like, I didn't see you on Wednesday, it was a Friday or this says you were wearing a red blouse, but when you were with me, you wore that pretty yellow dress...etc. etc.
That being said, guys do make up shit for whatever reason. I may have posted this one, but here is a good example:
There is a chica I once lived with and she was very possessive. When I was living with another chica she would visit my house and tell her I was on loan, and that she will be with me in the end. She even brought me gifts for my Birthday and Christmas.
So one night after I had become single again, I hear rocks hitting my second story bedroom window at 3am. I look outside and there she is. I go downstairs and let her in. She tells me this story about a goofy white guy that wants to stay with her. He says the chicas all lie to him and play him for a fool, and that he is changing and won't be a victim any longer. So after listening to him, he asks if she will spend the night with him. She agrees under the conditions that he buy her drinks for 2 hours and then meets her outside of the bar at 2:30 when she gets off. He agrees.
At 2:30 she hides in the back and has other girls tell him she has left already. Then she jumps in a taxi and goes to my home unannounced and wakes me up. She tells me the story and then we get busy. She soon falls asleep and the next morning, I am reading a site, and this guy is saying he had an overnight date with this chica for free. When she wakes up, I ask her who was the "career victim" she stood up...and of course it was the guy who posted the story on the other site.
So for whatever reason, guys sometimes do improvise on their stories and accounts with these chicas.