I've got to admit, I am somewhat surprised that some responses are pretty much to the point, and direct,,,,and still only have one side of the story,,,,,,but your right.
Example of not black and white.
I sold a mare a few years ago,,,,in foal,,,,,,on payments,,,,,,,,,but I retained ALL paperwork until the mare was paid in full.
The mare was to be paid for in 6 months,,,,,,,8 months later, the mare was not paid off and the foal was delivered and already sold. Then, the buyer of the foal came after me. This buyer had paid for the foal in full and I WOULD turn over paperwork to her, now..........well, with a lawyer, I did not. I did turn over the foals paperwork, almost 5 months later, a total of 13 months, when the mare was paid for in full.
My point.
If this person that bought my mare, came on here and wrote,
"What do you think? I purchased a mare 8 months ago, she was in foal. The seller now refuses to turn over paper work for that baby."
Would I then be a seller with unscrulpulous practices? I would hope not,,,,but with the example I have given you, you pretty much got two sides, not one.
Sign the paper,,,,,,,it's just not always that black and white.
Yes there are b/w situations, in which case, I always think they should sign.
Just my small opinion.