A witness in a criminal proceeding only has one opportunity to articulate their position clearly and plainly - there are no do-overs. During preparation, counsel must be alert to the use of ambiguous or imprecise language that does not accurately convey what the witness intends to say.
For example, there is a significant difference between saying “I don’t recall” and “that didn’t happen” in response to a suggestion made by opposing counsel during cross-examination. “I don’t recall” leaves open the possibility that the suggestion may be true, whereas “that didn’t happen” is a clear denial of it.
A judge or jury will scrutinize the exact words that a witness uses in assessing whether the prosecution has proven an allegation beyond a reasonable doubt. It would be unfortunate to have the credibility and/or reliability of a witness undermined due to a misuse of language.