That's what I thought, but you should know that he is kind of the dynamic of the jhana_insight yahoo group too.
I would say that his teachings are 95% consistent with theravada (you can find a pdf about a prayer that sounds mahayana to me on his website, and also one audio file about tonglen). You can find more of the mahayana stuff on the jhana_insight group (but it's still pretty rare), but it's always brought as a sharing experience in a theravadin context (an example would be his response to someone asking him how vipassana is viewed in tibetan buddhism).
I personnally am not attracted at all by any kind of mahayana, and I am very fond of his teachings. Anyway, maybe you should also take off the jhana_insight group, I don't know...
Please don't hesitate to correct my english if you feel to