Can't blame you. I sympathize with them about the wheel but the reason they are a new customer to you is simply because they need help with their lawsuit. That, and they need a wheel put on their car.
The truth is that they don't need some written declaration from you that their wheel fell off. All they need is a picture of the three-legged dog and maybe a tow receipt + shop receipt for engine job w/ dates, etc.
Any nutlesss monkey can see that the wheel fell off, they don't need a specialist to affirm this.