How do I make the distinction between editing an answer to add content (detail) vs. just answering that question?

Question

I have a question that has the right answer, but it's not very detailed:

How do Optical/Laser Mice work?

I'm at a dilemma here, I want to give the answerer the rep that he deserves as he is correct, but I feel that I'd be adding a LOT of content to his answer with my edit. But if I added my own answer, I potentially take away from rep that he may have collected. What do I do in these type of situations?

Note: I'm not going to be adding any novel new content, meaning the answers will be the same, but the amount of detail will be enlarged.

Answer 1

If you feel that your answer deserves a separate answer than editing the existing answer, by all means do post the answer. As for giving the answerer his rep, you could add a bounty.

Answer 2

If you do not change the intent of the answer and solely add more detail then you could just do it.