68, but simply to allude to the requirement that the serious irregularity must result in substantial injustice. The Court said it would not attempt the "impossible task" of defining what is an "issue", but he rejected three "suggested yardsticks" put forward in the authorities, which rely, to a certain extent, on the formulation of issues in the "list of issues" in the arbitration.  The question should be approached by considering the ordinary and natural meaning of the word "issue", and accepted PIC's submission that the assumption of responsibility question was an issue within the meaning of section 68(2)(d).  Although it could be difficult to decide where the line demarking issues from arguments falls, on the facts, almost the whole of Dow's claim could have depended upon how the assumption of responsibility question was resolved. On the question of whether that issue was "put to" the tribunal, PIC had put the issue about assumption of responsibility to the tribunal in its second pre-hearing memorial, which contained a sub-section headed "PIC did not assume responsibility for Dow's losses".  The Court rejected Dow's argument that PIC had withdrawn or qualified the issue, either through its list of issues or closing remarks made by counsel. As regards the question of whether the tribunal had dealt with the issue under section 68(2)(d), the authorities show that: This depends upon a consideration of the award. The tribunal does not have to set out every step by which they reach their conclusion, or deal with every point