A plaintiff sued a defendant for personal injuries arising from an automobile accident. During his case-in-chief, the plaintiff brought an eyewitness to the stand. The defendant was permitted on cross-examination to question the credibility of the eyewitness, even though no questions relating to credibility had been asked on direct examination. The judge then permitted the eyewitness to remain in the courtroom after testifying, despite the defendant's objection that the eyewitness was expected to be recalled for further cross-examination. The defendant was called as an adverse witness by the plaintiff, and the judge permitted the plaintiff's attorney to ask the defendant leading questions on direct examination. The judge then allowed the defendant's attorney to impeach the defendant's credibility on cross-examination.Which of the judge's decisions was in error?
A) Allowing the defendant's attorney to impeach the defendant's credibility on cross-examination.
B) Allowing the plaintiff's attorney to ask the defendant leading questions during direct examination.
C) Allowing cross-examination about the credibility of the eyewitness.
D) Allowing the eyewitness to remain in the courtroom after testifying.