He is signalling that he doesn't think Aboriginals are heathens at all, a bit like adding a wink at the end of a sentence so people know you're not serious.
Now, be careful not to add the g in this sound because it's often represented by an ng spelling, which in British English tends to be silent especially at the end of a word.
注意不要在这个音中添加 g 音,因为它通常由 ng 拼写来表示,而在英式英语中,尤其在一个单词末,g 通常不发音。