Around the time of the amending Act, the Bond companies' advertising campaign had increased their market share at the expense of the principal South Australian brewer.

Although all parties conceded that the increase in the deposit disadvantages the Bond companies, the question to be resolved was whether it was permissible for the state legislation to disadvantage interstate beer over local beer, if it on its surface was directed at solving an environmental problem.

The joint judgment by Mason CJ, Brennan, Deane, Dawson and Toohey JJ outlines the reasons why the 1986 legislation is not appropriate and adapted to the protection of the environment.

Furthermore, the judges did not think that the litter problem or the need to conserve energy resources provided a justification for the implementation of this scheme; they made reference to the quantitative impact of such a law, and the fact that alternative measures were open to the legislature to achieve these aims.

The joint judgment of Gaudron and McHugh JJ accepted the question of whether a law is appropriate and adapted, but also provided some guidance as to discrimination: "the essence of the legal notion of discrimination lies in the unequal treatment of equals, and, conversely, in the equal treatment of unequals".