I don't know if I agree with this. I think it's important for different members of the (small) team to interview someone they potentially, and most likely, will be working with. I'm a designer, but I would want to talk to someone interviewing as a PM, analyst or dev, since that makes up my team on any given client project.

I fully agree with this. In team environments it's extremely important for the team to review potential new members. It's also important for a the group to come to a decision.