On this occasion in South Australia the block voting system did not result in the usual landslide majority for one party,[7] with support divided among the various candidates.

[12] Thus the government could only expect a majority of votes,[e] with the support of the Labour leaning independent from Victoria, William Trenwith,[f] or the conservative senator from Tasmania, Henry Dobson, who was elected as part of the Tariff Reform party.

On 1 June 1907 Barton J declared the election of Vardon to have been absolutely void, by reference to s205(iii) of the Commonwealth Electoral Act 1902.

[8][19] On 8 June 1907 the Attorney-General, Littleton Groom KC, set out that, in his opinion, section 13 of the Constitution,[5] prevented a supplementary election being held, despite the words of s 205(iii) of the Commonwealth Electoral Act 1902.

Of the Labour Party candidates, Crosby had died and Blundell had been elected to the South Australian House of Assembly.

[23] While the election was for a six-year term, because O'Loghlin was purportedly appointed to a casual vacancy under section 15 of the Constitution,[5] he would only have held office until 30 June 1910.

The report emphasised the need for senators to be "directly chosen by the people", to which the appointment to fill a casual vacancy was the exception.

The two Labour senators provided an addendum to the report that the question could only be resolved by reference to the High Court.

Enabling legislation was subsequently passed by the Parliament, including a requirement that any hearing be in open court.

The primary argument put for Vardon before the High Court was the dominant requirement that senators be chosen by popular election.

The High Court declared that appointment of O'Loghlin by the Houses of Parliament of South Australia was void.

The majority judgment of Griffith CJ, Barton and Higgins JJ held that section 7 of the Constitution,[5] requiring senators to be directly chosen by the people of the State, was the 'dominant provision'.

[3] Isaacs J gave a concurring judgment setting out his own reasons, in which he similarly emphasised the requirement of section 7 that the senators be directly chosen by the people, stating this was "more than a mere direction, more even than a simple mandate as to the mode of election; it describes the composition of the Houses themselves, so as to express the essential nature of these branches of the Parliament.

"(Section) 15 of the Constitution was not framed with the object of meeting numerous instances of irregular Senate elections, but of providing for possible but rare contingencies of the abnormal termination of the service of senators; so rare that departures from the fundamental principles of representation through popular election would be really inappreciable because infrequent and possibly of short duration".

[4] In light of the High Court decision the question raised whether Vardon, O'Loghlin or Albert Palmer,[j] were entitled to keep the allowances they had received whilst they sat in parliament.

[38] The Parliament resolved the question by enacting legislation to legalise the payments that had been made to Vardon, O'Loghlin and Palmer.

The appointment of O'Loghlin remains the only occasion on which a matter has been referred to the Senate Committee of Disputed Returns and Qualifications.