If the Turkey was still in the original package, I would probably eat it. I don't think the crock pot was the best choice, however. That method just prolongs the amount of time the outside of the meat (where the bacteria will be) is in the ideal growth zone.
Your only real risk is from Staph toxin, which is heat stable. Every pathogenic bacteria will be killed by proper cooking. You have more danger of getting sick from the left overs than the properly cooked breast. A Turkey breast is much safer than a whole turkey, because the area that is likely to have the highest concentration of pathogenic bacteria (Salmonella) is exposed.
While there is a risk of staph toxin, it seems slight to me if the product was still in its original package, and the water was still "very cold".