I was at a sushi restaurant with my boyfriend, Peter, and the waitress accidently put an $11 entrée on the bill that we had not ordered. After inquiring about the item the waitress apologized. We asked the waitress would the money be transferred back to his account in 24 hours and she responded by saying "yes it should" and touched the back of her hair/neck (red flag). "May I have your card back I'll be right back" and left for about 10 minutes to fix the mistake. (We did not mind at all, it was a busy night and mistakes happen, also it wasn't my card ). I took the chance to tell Peter, you know she did a self-soothing touch when she said your money should be back on the card by tomorrow and she hadn't done that earlier in the night in her normal baseline, which means she was not confident about that statement and I would double check your account tomorrow! He laughed and said okay but the beauties of reading people can sure go along way when it affects your finances!
Disclaimer: it's always important to look for context, she could have just been uncomfortable she made the mistake!