Who is the bigger Liar?

Who is the bigger liar? They are both liars. However, each individual lied about different things. James Frey on one hand lied about situations that he encountered. He added facts and used a lot of exaggeration to make his stories sound more exciting and appealing. This is not right because he wrote a memoir about his life, but half of it was not true. So why did he even write a memoir?
On the other hand, Grey Owl lied about his identity. He said that he was a full-blooded native Indian, when in fact he was an Englishman. He also stated that he did not enter the wilderness until he was 18. Although both of these men used lies in their stories, I would say that Grey Owl was the bigger liar because he lied about his identity rather than facts.