i did not interview at this particular institution, however i would not make too much out of not hearing from them. since theyre your #1, you should absolutely inform them of it. pd responses are highly variable. some pds respond to everyone, some to noone, some only to highly rated candidates. and if they do respond, the only 2 responses with any real weight are: 1) you are ranked to match, and 2) not likely. getting either of these responses is pretty rare.
now, having already emailed the pd that theyre your #1, one thing to consider is having one of your pathology letter writers calling the program on your behalf.
out of curiosity, are you doing you schooling in the northeast ohio area?