However the conflict is not strong to hold his evidence is of no value when the documentary evidence speaks for itself. It is trite the best evidence to challenge documentary evidence is same Documentary evidence. – Nwodo, JCA. OLAM v. Intercontinental Bank (2009)
EVIDENCE GIVEN IN ANOTHER CASE, HOW MAY BE USED IN PRESENT CASE
Evidence given by a witness in another case may be used to impeach his credit if, in the later case, he says something different; but what he said in the earlier case does not become evidence in the later case. And a judgment given in another case can, in appropriate cases, be put in a later suit, to prevent the re-opening of the same question. One hopes that the indiscriminate introduction of other proceedings into a trial will be discontinued.
— Bairamian, F.J. Owonyin v. Omotosho (1961) – F.S.C.249/1960