Chicken processing practices vary a lot, some places have pretty good practices, some not so much. Many places are moving away from the methods that caused the problem with your chicken to more humane methods, they have a conveyor belt that gradually changes the content of the air so the chicken dies peacefully, no shock needed.
There is also a huge problem with antibiotic resistance bacteria and a huge cause of that is antibiotic use in chickens, so more important than organic is looking for chicken that is raised without antibiotics.
In the U.S., Perdue Farms made the switch to antibiotic free chicken starting in 2007 and today all their chicken is raised antibiotic free.
From the book "Big Chicken" by Maryn McKenna, from an NPR story.
When we give animals antibiotics, those antibiotics, for the most part, are given in their food and water. So they go into the animal's guts. They make some of those bacteria [in the gut] resistant. ... That bacteria contaminates [the animal's] meat. We eat the meat. And then we develop the foodborne illnesses that ... happen to be antibiotic-resistant. ...
The terms "cage free" means nothing when buying chicken, meat chickens are never put in cages, hormone free also means nothing, it's illegal to use hormones in chicken.
McKenna's aim in writing the book is not to scare people away from eating poultry; rather, she hopes to improve the quality of the chicken we consume. "I think meat eating is going to remain with us as a culture," she says. "Therefore, I want to see meat producing get better, get better for the animals and also get safer for us. I do think it's possible to get there."
Here is a link to the full story from NPR
NPR Big Chicken