Because I haven't had the chance to play the episode 3, (EU PS3 user), I did check some online video walkthroughs. SO please forgive if I do get anything wrong.
I noticed that Lee and Kenny both go to back the pharmacy from episode 1 and I thought it would have been cool if you saw the person you failed to save back at the pharmacy. You know seeing zombified Clarey/Doug walking around that place.
Also maybe have a small interaction with them. But alas no :(