UK Citizenship with Grandparent who is a British Citizen Question

Hi, i'm trying to find some clarification regarding an Australian citizen who has two grandparents who were born in Scotland and if they are eligible for UK Citizenship by Double Descent?

I've emailed and tried to phone EVERYONE and am getting conflicting answers and i'm currently waiting for the UK border agency to get back to me and a whole heap of other people.

This male was born in Australia in February, 1983.
His father was born in Australia in May, 1957.
His mother was born in Australia in January, 1960.
They were never married.

His grandmother was born in Glasgow Scotland in 1937.
His grandfather was born in Glasgow Scotland around 1930 (we're unsure of the exact date yet)

Is there any possibility he can actually be a British Citizen by Descent?

I was looking at the following page....

http://www.ukba.homeoffice.gov.uk/briti … noverseas/


And came across this paragraph..

"when you were born, you had a parent who was a citizen of the United Kingdom and Colonies because he/she was born, adopted, naturalised or registered in the United Kingdom (except in certain circumstances), or because one of your grandparents was."

I'm very confused and I hope someone can help answer this?

Thank you so much!!!