Thinking and communication skills are at least as important as technical ability - it's important to assess how they learn. Myers' approach involves paired programming (whether the team uses paired programming or not). He feels that it provides a good simulated environment within which to assess the candidate’s confidence, technical competence, and communication skills.
It's important to remember that interviewing is a two-sided experience. Myers also mentions a technique called "Extreme Interviewing" which is like his paired programming approach taken to a massive level. In addition to the chance to interview lots of people all at once, Extreme Interviewing also gives interviewees a taste of the “bull pen” phenomenon – working in a noisy room – that usually takes place in small Agile teams.