"The Defendant [was] entitled to contend that the use of force by PC Heath against the Claimant and his arrest of the Claimant on15th June 1997 [was] lawful and, save as to the fact of his acquittal, and save for the purpose of proving any inconsistent statement, the Claimant [was] not entitled in this claim to rely upon the judgment given at the Crown Court at Luton on20th August 1998 in the criminal proceeding brought against him."