Before I post my own theory of the hidden purpose of the Genesis contradiction, some comments on the objections.

The first objection was that the numerous self-contradictions of the bible are easily explained by the fact that the bible was written by many authors. This might be true for most of the contradictions, but I do not think it applies here. While the two creation stories probably stem from different sources, they were at least put together to the book Genesis by one final editor. This editor had to be aware of the contradictions, but nevertheless decided for some reason to put both creations stories together, with the heathen one at the very beginning. It's easy to walk away thinking: "Ha, ha - those bible writers didn't even manage to get their own tales straight!" But in my opinion there's more to it.

The second objection was a link to a website that claimed that there is no contradiction. Well, the only arguments presented were a theory that the second creation story was not referring to all plants and animals, but only to a few that were created after Man as a sort of late add-on. The bible does not mention that they were an add-on, to the only reason for that theory is that otherwise we had a contradiction. Also some sentences of the second story were written in a different tempus, the plusquamperfect, which was claimed to shed some doubt on the order of creation.

However, the first creation story clearly refers to all plants and animals, and the second one introduced a different creation order not only in tempus but also in causality. Just the needs of the already created man caused the creation of the plants and animals. So the theories about the add-on animals and the meaning of the plusquamperfect are apparently nonsense. In fact the contradiction in the two Genesis stories is even more obvious in the original Hebraic text (where the number of involved gods also differs). You had to be a very fanatic believer not to see it. However the bible was not written for fanatic YECs that believe everything literally, but for educated, normal people with an open mind.

If the bible editor had not intended a contradiction, he could have easily described the creation in a clear and consistent way that doesn't require strange interpretation theories by apologists.

So now the question is: When we assume that the contradiction between the two creation stories was intentional and meant to be noticed by the brighter part of the target audience, what was the intention? I don't have much time at the moment, but will post my theory later.