How should judges judge for this judgment? There are reasons not to implement all potential rulings. If they were to order the one who snatched the metal to pay for it, that would not be the correct ruling, because there are not two witnesses who saw him snatch it, and the court does not force payment based on the testimony of one witness. If they were to accept his claim and exempt him entirely, that would not be the correct ruling, because there is one witness who testified against him. If they were to order him to take an oath, which is the usual response to counter the testimony of one witness, didn’t he say that he did in fact snatch it, and since he said that he snatched it and there is no proof that it is his, he is like a robber, and the court does not allow a robber to take an oath.
אמר להו רבי אבא: הוי מחויב שבועה שאינו יכול לישבע, וכל המחויב שבועה שאינו יכול לישבע – משלם.
R' Abba said to them: He is one who is liable to take an oath who is unable to take an oath, and anyone who is liable to take an oath who is unable to take an oath is liable to pay. The Rabbis who were studying before Abaye thought that the case of the witness to the years of profiting and R' Abba’s case are similar, in that since the possessor is unable to take an oath to refute the witness, as he concedes that he profited from the land for those years, he should have to pay for his consumption of the produce.