Ds tends not to be empathic, very similar to a lot of other people's descriptions on this thread, but, he seems to be able to 'get it' retrospectively, if we spend a lot of time afterwards talking about an event when he would have felt a similar way and relating his feelings to how the other person felt.
That said, he then can't generalise it to the next time he sees a similar situation, although I think he does eventually to some extent and he is improving as he gets older, I suppose as he has more and more experiences to compare.
He has learned that he should be sympathetic, say, when someone is ill. So every single morning when I come downstairs all bleary eyed, grey and exhausted he will ask me if I'm poorly. If I say yes, he makes sympathetic-ish noises ("oh dear, never mind, hope you feel better soon" etc) but only because that's what he's learned he should do, not because he 'feels' sorry or bad for me being ill - if that makes any sense. There's no actual feeling behind the words, so it doesn't fool me, although he must be improving, because he can fool people that don't know him very well sometimes these days