Nick, I think you're thinking about the episode where Phoebe dates the "shrink", named Roger.
While both Raj and Roger's observations & advice were uninvited and unwanted, Raj's came from a place of love, an understanding of the people borne from years of friendship and a sincere desire to help. While Roger's unsolicited advice just seemed to come from an almost pathological need to point out everyone's dysfunctions, if not a need to show off his expertise... "I don't Know... I mean, we just met.. but.." and in a minute or less he outlines their dysfunctions and their origins, then off he and Phoebe go, leaving the friend sputtering, and attempting to say otherwise.. Yeah, they all hated Roger by the end of the episode, even Phoebe, lol!