I have no idea what the interviewers motive was. I'm certain he has a different story. From my perspective he asked me to show certain functionality and then shouted over me every time I tried. After 30 minutes I hung up.
edit: obviously it wasn't personal, there is no way we had ever crossed paths before. personally I think had no idea how to conduct a technical interview and thought he was being tough on me. anyways, its just one experience. obviously people make it through the procces. I do think they could try to be a little more responsible given that they just asked for a week of your time