Practice and Procedure — Costs — Trial of preliminary question as to liability — Residual questions remaining for determination — Trial judge ordered that costs of the trial of the preliminary question follow the event — Application for leave to appeal — Whether, on any view, the outcome of the trial of a preliminary question entitled the plaintiff to compensation of some substance — Whether trial judge should have awaited the determination of all issues in the proceeding before making any costs order — Supreme Court (General Civil Procedure) Rules 2005, rr 63.02, 63.01(1) and 63.04(2) considered.