Sir, Both are on oath, two persons making completely contradictory irreconcilable statements , both can't be true , and both have a direct impact on accused, what would the court believe?
A deposes B was present and a witness to the crime by C
B deposes he was not present and has no idea of the crime committed by C
If benefit of doubt given to accused, A is lying.
w/o benefit of doubt also, court still can't decide that C is guilty as B is denying the fact assuming no other evidence exists.
since both A and B are deposing in full consciousness, one of them must be lying?perjury?