Carver have met Clementine before the outbreak. (Theory)
I know this is a pretty stupid theory with many holes in it but her me out...
We know that Career was an engineer before the outbreak, that's how they were able to get Howes in that good shape that it was in when Clem and her group came there. (I think you learn that from scrapped audiofils)
We also know that Clems dad Ed was an engineer (Clem can tell Lee that in the Drugstore). So it is an possibility that they worked together or at least at the same company. Even if Clem lived a little bit outside Atlanta and Howes were set somere in Virginia (I think can't remember) doesn't mean Carver lived there before.
There's also in Season 2 episode 2 if you tell Carver your dads name he says "Strong name I like him already" maybe because they were friends and he recognised Clems hat that was Eds before.
Carver also wants to win over Clem to his side in episode 3 that i pretty obvious, but it may not only be because he thinks Clem has good potential of surviving an being a good leader. It may be because he know her when she was little and wants to protect her on a distance. It can also be the reason for Clem not recognizing Carver, because she was to young.
It is also pretty obvious that he wouldn't say anything because Clem wouldn't believe him or even care.
I am sure I have forgotten something that makes this theory more believable, but what do you think?