Final answer:
Expert witnesses should maintain their positions during cross-examination for credibility and professionalism, avoiding areas outside of their expertise and evasive responses.
Step-by-step explanation:
During a cross-examination, expert witnesses should maintain the same positions taken during direct testimony. This consistency is crucial because the credibility of the expert is based on their specialized knowledge and consistent application of professional standards. An expert should not address areas outside of their expertise, as doing so could undermine the trustworthiness of their testimony. Responding evasively or ambiguously to tough questions may also harm an expert's credibility. Although a friendly demeanor towards opposing counsel is generally positive, appreciation should be limited to maintaining professionalism rather than compromising impartiality.