If they are reporting a bug in the app one way to prevent this is a help/about that has an e-mail address (or some other contact type--but e-mail is best) and also in your description note that they can e-mail you directly for any changes/suggestions/help -- this generally prevents 1's for bugs-- and you can deal with the "disgruntled" 1'r and calm them down and give them a fix.
I understand that happened but could be happening to a very small percentage of people that download it, and by giving it a 1 star review immediately, it may take people away from it.
That being said, of course I would probably be pissed myself if I wanted to try an app and then it crashed as I started it.