Supported by his family and a wide variety of community organizations, Hall thus took the school board to court in a two-day hearing that began on May 6, 2002. Hall's lawyer, David Corbett, argued that the denial of his request violated the Ontario Education Act, which requires school boards in the province not to discriminate. The school board, on the other hand, argued that court interference in its decision would amount to denying its religious freedom.
Corbett argued that an organization which accepts public funding (Catholic school boards in Ontario are fully funded in the same manner as public schools) has to be accountable to the same laws (including anti-discrimination laws) as other public institutions. The school board's lawyer countered that Section 93 of the Canadian constitution protects the Catholic board's rights to conduct its affairs in accordance with Catholic teaching.
In addition, Corbett noted that while extramarital sex is also contrary to Catholic teaching, the school board had previously allowed pregnant students to attend the prom.
On May 10, Justice Robert McKinnon granted an interlocutory injunction ordering that Hall be allowed to attend the prom with Dumond. The justice also ordered that the school not cancel the prom. He did not decide on the larger issues raised by the case, leaving those to be heard at a later trial. Hall attended the Prom with Dumond that evening. In 2005, Marc Hall dropped the case.