Mr. Smith, an Australian citizen, began working with a company in Oman in November 2015. As part of his work arrangement, he was required to work a 35 days on and 35 days off rotation. At the end of each rotation, Mr Smith departed from Oman and, on several occasions, returned to Australia to visit family and friends. While he was working in Oman, he lived in a single room apartment with an ensuite, bed, lounge area and a mini kitchen. However, he did not have exclusive possession of his accommodation as he shared it with another employee who worked a complementary roster.

Required:

Provide an explanation of the key factors considered necessary to determine whether Mr. Smith is an Australian resident or non-resident for tax purposes.