you know why hes hittin the button right....hes actually creating the tremolo effect with his strumming hand, and hes tapping all the notes with his fret hand...ie. since hes tapping he doesnt need to strum...fyi
I thought the button was kind of like a mute button, which is why the music was so choppy sounding. Like Saosin said, he's hammering with his fret hand. On an electric guitar, you only need a little bit of pressure to make the sound. It's not nearly as hard to get it to wha wha out as it is on an acoustic.