If a Bill did not touch him, then he is not down by contact. However, if the whistle was blown, then he is ruled down and the play is over.
So yes, Eric Wood made a heads up play in tackling him. I don't know if a whistle was blown or not. I was half distracted by my kid at the time.
Edit: I thought it was a fumble at first, but on replay, Burris' knee was on the ground, so the moment Wood hit him, he was down.