I have a hard time believing that storing injectors for a year, packaged correctly, would be an issue. In racing and pulling circles this is done all the time. I have done this many times and have installed my cp3s and injectors that have been sitting packaged on the shelf for over a year and have never had an issue.
Now i can see if they are left open or the diesel had water in it but i don't see blaming the injectors being stored the problem.
Looking at that photo, i can see contamination and/or rust from improper storage could surely be an issue.
Just my experience in over ten years of racing and storing fuel parts while new builds are happening.
X2 I put an LBZ back together that was taken apart by another shop and the truck sat for two years. The injectors were not seal or cleaned and the truck started and ran fine after I put it together.