I was watching "The Big Bang Theory" and in episode 07 of season 3, Leonard asked his girlfriend the following question
Penny: I hear you don’t like my stuffed animals, my driving or my punctuality.
Leonard: What? Who would tell you something like that? Why would you tell her something like that?
Penny: It doesn’t matter why he [Sheldon] told me. It’s true, isn’t it?
I'm wondering why he didn't use simple past: "Who told you something like that?"
What's the difference?
Source: Show Script