In Hodges' trial, the expert testimony was entirely believable.  It can be more difficult to tell what happened when various witnesses report different parts of a story – or contradict one another.  The Duke of Norfolke brought suit against his wife for divorce, and produced witnesses who testified that his wife had joined in adulterous union with Sir John Germaine.  These witnesses were foreigners, who had to have translators, but they made it perfectly clear that they had seen Lady Mary in bed with Sir John.  The witnesses for the Duchess, on the other hand, were truculent, and showed every sign of being unwilling to testify truthfully.  The Lords Spiritual and Temporal found for the Duke.