Halakhah for Sanhedrin 64:5

And both capital cases and financial cases are included in this commandment, as it is stated (Leviticus 24:22), "One judgement shall there be for you." But the Sages said that in order not to close the door in front of borrowers, that we not require inquiry and investigation of the witnesses of money [cases]. How is this? [If] the witnesses said, "This one lent that one a hundred in front of us in year x" - even though they were not precise about the month and the place in which he borrowed, and not which coin the hundred was [composed of, if] their testimony was the same about the value of the hundred, their testimony stands with that. And about what are these words speaking? About admission, loans, gifts, sales and that which is similar to them. But with cases of penalties, we require inquiry and investigation, and there is no need to say with lashes and exile [that they are required]. And likewise, they, may their memory be blessed, said (Sanhedrin 32b) that if the judge sees that the case is forged, even with the cases of admissions and loans, he needs to do inquiry and investigation upon them. And if they contradicted one another in the investigations and inquiries, their testimony is nullified; but if they contradicted each other in the checks, their testimony stands. How is this? If the one said, "He borrowed in Nissan," and the other said, "No, rather [it was] in Iyar"; or the one said, "In Jerusalem," and the other said, "No, rather [it was] in Lod." And so [too,] the one said, "He borrowed a barrel of wine," and the other said, "No, rather [it was] a barrel of oil" - this is investigation and inquiry, and [so] their testimony is nullified. But if the one said, "He borrowed a black hundred," and the second said a white hundred - and the value of both of them is the same - or the one said, "They were in the upper floor when he lent to him" and the second said on the bottom floor - this is checks and their testimony stands. [These] and the rest of its details are in Tractate Sanhedrin (Chapters 4 and 5).