You asked about the following case:

Reuben brought a claim against Simeon before the court. He said:

“I sold an object to a bishop for three pounds in pennies. The bishop later told me, ‘I don’t have any pennies, so instead I’ll give you five half-pounds of silver corresponding to those three pounds.’

“I was pleased with this proposal and answered, ‘Yes, do that.’ The bishop sent his agent with me to his treasurer and instructed the treasurer to give me five half-pounds of silver.

“We found the treasurer with Simeon. When the bishop’s agent spoke to the treasurer, Simeon said, ‘I’ve already exchanged the bishop’s silver at that rate. The silver is now in my possession and the pennies are ready here.’

“I told him, ‘I’ll accept only the silver.’ Simeon then spoke privately with the treasurer. Whatever he said caused the treasurer to give me only the original three pounds in pennies.

“I now demand from Simeon the additional amount that I lost because of his intervention.”

Simeon answered:

“I didn’t cause Reuben a loss. On the contrary, he caused me a loss. He pressed the treasurer to take the silver away from me, and I had to give the treasurer a gift before he would leave it in my possession. I’m the one who suffered a loss because of Reuben.”

My opinion is that Reuben has no claim against Simeon, even according to Reuben’s own account. Simeon neither deprived him of anything nor caused him damage, since Reuben received full payment for the object he had sold.

If Reuben’s claim concerns the additional value of the silver, he never acquired any legal right to that silver. Our teachers taught:

“If someone sees a lost object and falls upon it, but another person comes and takes possession of it, the person who took possession acquires it.”

Reuben never received the silver and didn’t even touch it. All the more so, he didn’t acquire ownership of it.