I've been in management for about 15 years and have hired many people. My take-away is that standard HR interview practices ("Tell me about a time when you had a conflict with a coworker...") are basically a popularity contest that strongly favors extroverts and people with good story-telling and language skills. I suppose these techniques are good if that's primarily what you are looking for. However, if you are hiring for actual technical skills, these interview techniques are worse than useless, they are discriminatory.

Also, HR people, in my experience, are quite under-educated when it comes to interview techniques. I've worked with about dozen different HR people over the years and none of them had any kind of imagination or technical expertise when it came to interviewing. In my organization and in other similar organizations where I have peers, any deviation from the standard HR interview is entirely driven by managers who are sick of the usual HR crap.