Ok, this is a weird bug that I've personally never seen before. During certain scripted conversations between npc's, one of the npc's that is supposed to be there is not, so the conversation becomes very one sided. An example would be the Alik'r warriors that come to Whiterun after the first dragon is killed. I traveled back to Whiterun and there the two warriors were, but no guard. They kept talking like the guard was still present but he was not, and then they approached me like normal.

Has anyone else run into this issue and is there something to do so that it doesn't happen again?