Unfair or Unjust?

I have before wondered about the difference - if there is one - between what's (un)fair and what's (un)just. See, for example, p. 42, fn. 1 of my 'Fairness between Competing Claims' in Res Publica 16:1 earlier this year. I'm not convinced that there is any ordinary language distinction that native speakers recognize (like, say, that between mistakes and accidents).

Whilst reading about Liverpool's draw with Sunderland yesterday, however, I notice that Steve Bruce described the referee's decision to allow Liverpool's opener as "unjust, unfair and wrong". A statement from the Professional Game Match Officials (a body I'd never heard of either) argued that the decision was in fact correct, but I'm not here to debate either its substantive merits nor interesting questions about whether the referee's decision can be both unjust and the correct one for him to have made. Rather, I'm intrigued by Bruce's phrasing.

I guess it suggests that he thinks there is a difference between being unjust and unfair (and a further issue of being wrong). Presumably his distinction between what's unjust and merely unfair can't rest on an appeal to anything like the basic structure of society either, since this decision wouldn't violate Rawls' principles of justice. I wonder what he had in mind?