 The case of Jaggard v. Dickinson ( 1980 ) held that even a drunken belief will support the defence even though this allows drunkenness to negate basic intent ; and Lloyd v. DPP ( 1992 ) ruled that a motorist who damages a wheel clamp to free his car , having parked on another 's property knowing of the risk of being clamped , does not have a lawful excuse under the Act even if he makes a mistake of law . 
