Whenever I've conducted interviews in the past, I've gone out of my way to help the candidates relax. Need to use Google? Go ahead, I do literally all the time. Need some advice, something explained? Just ask, that's why we have peers. Nobody writes code on a whiteboard, with no docs, with three people watching, silently taking notes.
Interviews should reflect the environment within which the job is actually done, and allow the candidate to demonstrate what they're good at, instead of treating them like a circus animal jumping through hoops, giving them performance anxiety.
For my most recent job, they circumvented my interview entirely and just did a few days of contract work instead. That way the company gets usable work, the candidate gets paid, and it filters out those who can interview really well but may not be a good company fit.