After entering the CDC and getting in the elevator, I think Daryl asks about Dr's going around carrying that kind of heat (his AR), to which he says something like, "I had familiarize myself with it... but you all look harmless" and then he says something that when I watched originally a few years ago didn't mean much. But now his comment to Carl of, "except you, I'm gonna keep my eye on you".

Maybe a little foreshadowing or maybe not, just interesting knowing how Carl is now compared to then.

 

From a first glance yes, but knowing what we know now, it seems like it could be a little chuckle between the writers.