Welcome BRMee,
Don't beat yourself up over it. Coulda,shoulda,woulda, is not going to help anything. Give the DEC the benefit of the doubt, probably a good reason, they maybe just couldn't tell you. It's very apparent you care about raising you kid the right way and I believe you did the right thing. Sometimes things just don't work out. I hope you and your family shoot monster bucks and fill your freezer after that. You deserve it. Good luck!