Challenging witness evidence

• If a witness’s evidence is challenged, or a finding sought adverse to their evidence, must that witness be called to answer in cross-examination?
• If a witness, whether lay or expert, is not given an opportunity to explain points a defendant wishes to argue against, is a decision made without that opportunity fair to the complainant and to the complainant’s witness (expert or lay)?

What have each of these in common: Yosser, an allegedly dangerous dog; a holiday maker with acute gastroenteritis; a Bangladeshi whose UK citizenship was under challenge by the Home Office; and a deceased testator who wanted to leave her house to her daughter over the heads—and wishes—of the daughter’s brothers? An answer is that all have been recently in various appeals courts in circumstances where, in each case, an appeal was allowed because a respondent to the appeal had not given a witness (party, lay or expert witness) an opportunity to answer adverse allegations which were made later