The issue is "severe deficiencies" in the injector. That could mean anything, but the most likely answer is that it doesn't function correctly/consistently. This has actually been a problem with the other two generic injectors on the market as well.Anticompetitive practices always hurt the market, and therefor, the consumer.
On the other hand, it could mean that Mylan bought off the FDA and it's just delaying the product until 2017.