"We take it to be axiomatic that justice before a tribunal must not only be done, but also to be manifestly seen to be done. That applies as much in our view to a tribunal such as the Industrial Tribunal as it does to a formal court of law. Not only must there be no bias on the part of the tribunal but also the tribunal must not give the appearance of bias. Where there is an allegation of bias based on the conduct of one or more members of the tribunal at a hearing, the test is, in our view, an objective one: would the reasonable observer present at the hearing, not being a party, or associated with a party, to the proceedings but knowing the issues reasonably gain the impression of bias."
"That impression may be given by the appearance of a closed mind against a party on a matter which calls for decision by the tribunal when that party has not yet presented all his evidence relevant to the point, or had the opportunity of addressing the tribunal on that evidence."