Ok, so I went to work today and one of the girls I work with said that the squirrel was in the lobby area again yesterday.  She said that he was just sitting there and wouldn't leave, so she had to chase him out.  He went into the tree right outside and waited for her to leave so he could go back in.  I guess our boss feeds him, so he's used to coming in and being with people now.  Great.  I just hope he isn't there when I am because I will probably freak out again.