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In Cross-examination, counsel can seek to show that the witness's version of events is incorrect, or incompatible with previous statements. Evidence can be introduced to this effect if necessary. However, if the witness answers a question on a matter that is collateral to the case, the questioner will usually have to accept the answer as given, and not attempt to rebut it. This is to prevent the explosion of irrelevant questioning that would follow if such tactics were allowed.