Well he was the GG at the time of the dismissal..
10 November 1975
• GG Kerr seeks advice from High Court Chief Justice Garfield Barwick
• He wants to know if he has power to dismiss gov. Barwick says yes
• GG is supposed to seek advice only from his PM
11 November (Armistice Day also)
• Whitlam informs Liberal opposition he intend to hold half-Senate election break impasse
• At about 1.00 pm, Kerr sacks Whitlam
• At about 1.30 pm appoints Fraser as caretaker PM on condition he passes supply, calls election and intro. no new bills until after election
• Senate passes supply
• Fraser asks Kerr to dissolve parliament, call a double dissolution election