This is a quote from the wikipedia about walkie talkies.
'Another theory is that the man took it from Clementine's parents, this can be supported by Diana through the answer machine, saying Ed had a little "incident" with some crazy guy near the hotel, although this could have been a zombie.'
I haven't considered that the referenced 'crazy guy' could have been the crazy guy who was communicating with Clementine. Up to this point I had always interpreted 'crazy guy' as a walker.
Thoughts? Perhaps Clementine's creepy friend is a long-term stalker!