I think it's for both reasons. In The Short Second Life of Bree Tanner, it kind of points to these two answers.
Riley was deceived. He thought Victoria loved him. So, he lied to the newborns for her. However, like it's explained in Eclipse, he was her puppet. She was using him and the newborns.
posted over a year ago
yeah i thot that too but it just kind of makes me think did victoria tell him all this stuff amd he thot it was the truth so he told them or did he no the truth but lied anyway