I don't think it has anything to do with quality control, it's just the nature of glass and these things happen.  That is why you need to have several vials in you emergency kit.  You could be ok with the vial and then stuff up when giving the shot or something.  It cracks me up sometimes when they do this---script for one---because they use these things all the time and must know how imprtant it is to have these things for us and that these things happen.

Just get a script every time you see your doctor, and that way you can stock pile them, even when you don't need them just do it.  I always get a script for hydrocortisone tablets as well as suspension---just incase there is some earth quake (lol) anything, you just don't know when your are going to need them! Also Gastrolyte sachets.  They keep for ages.  I always get my monies worth now when I go to the docs and come away with all the scripts I need to stock things up.

JH