While the author says that GO is Object Oriented, I think the go language site http://golang.org/ implies that it is not object-oriented in the conventional sense. The author goes on to say "It is the lack of implementation inheritance that seems odd. Most of us are used to considering it as a necessary part of an OO language." suggesting that he is possibly presuming an Object Oriented approach.

Not all of the implementors of GO are fans of the Bjarne school of OO.

I think the author covered that by saying: "Go is an object-oriented language, but not in the style that most programmers these days think of OO."