If he hatched from a green shell, that makes him at the very least an F2 cross.... unless the Araucana or Ameraucana hen that laid his egg came from a line that laid green eggs instead of blue ones. Green-laying purebred Ameraucanas are something that's frequent enough in Canada that I look twice at their breeders before buying chicks, but if you're in the USA it shouldn't be too much of a problem, as they prefer their girls to lay blue.
Gold leakage happens most often in sex-linked crosses, in the male chicks. But I'm pretty sure there's one type of white plumage that can also leak gold, but I don't remember which one it is...
I wish I could help you more with finding the possible parentage of your cockerel. Maybe you could post pictures of your EE on this
thread? His parentage may be unknown, but if someday someone posts pictures of an EE matching yours and knows what chicken breeds went behind its creation, that could potentially solve your mystery