"The Tribunal considered it arguable that the ET (Employment Tribunal) had erred in law in failing to analyse whether, by virtue of custom and practice, there was (at least) an implied term that the appellant would be in a position to earn overtime, and that the employer was thus in fundamental breach by putting the appellant in a position where it was impossible for him to earn any overtime: see the appellant's skeleton argument at point (ix) sent on 18.5.01"