I think technical competence has to be part of it. If you know the person's references and those references are honest, you can ask them. But, I had one friend who had the fortune of always being surrounded by pretty bright, motivated, and competent people. For her first hire, she did a phone interview (international candidate), but was thinking more about issues like "does this guy seem like a good fit for the project in terms of interest" and only found out when he arrived that his technical expertise was far lower than what one would expect given his resume...
