Well, I don't know the answer to that to be honest. Because people on both sides lie, and I've been fooled before by students who I thought were slam dunks to match with us. I think to a point, many people are just uncomfortable stating negative feedback. No one wants to tell someone they are mediocre, or that they are a bottom of the list candidate. It's incredibly uncomfortable saying that to someone. And also, sometimes its truly not a lie. Someone can tell you they are ranking you highly, then just match the spots right above you. Or they can tell you they are ranking you highly in November, only to have something come up about you they didn't know about during the rank list meeting and then DNR you. This stuff happens. Virtually every year a resident brings up concerns about a student or two that weren't well known prior to the rank list meeting only to then see that person free fall on the list. So maybe what someone says earlier in the year wasn't a lie at the time.
The take home message is, whether it's lies or not, you should never trust career decisions based on the feedback you get from programs. Rank places in the order you want to go there.