I do this when it's appropriate. Where I'm not sure it applies is in the very common scenario of someone asking a question that doesn't really make a ton of sense. If I do a warm handoff, I'm implicitly endorsing their question, even if it's needlessly hostile or poorly formed or based on a misunderstanding. (I could take on the responsibility of fixing every bad question that comes to me, whether or not I'm the right person to ultimately answer it, but then I wouldn't have time to do my job.)