Original: Lord Chief Justice John Holt of the Queen's Bench apparently pronounced this error, for he announced that it was "better ducking in a Trinity, than a Michaelmas term", i.e. better carried out in summer than in winter.
Simplified: Lord Chief Justice John Holt (the person trying to have the judge find Foxby guilty) said this was not correct. He said that it was "better ducking in aTrinity, than a Michaelmas term", meaning it was better that a person be ducked in summer than in winter.