My argument isn't based on the 'authority' of Lewontin, but on the authority of what can be observed, i.e. that 'theories' based on philosophical naturalism are the only form of theory that is allowed in 'science'. Were that not true, then ID would be equally as valid.
Your argument is the fallacy of denying the antecedent because your opposition is based solely on the claim that Lewontin doesn't speak for all scientists, not on any evidence contrary to his statement.
Your's is based on the assertion that he does. Either that, or you're wanting to draw conclusions about science based on what could very we be nothing more than the self-absorbed musings of an over inflated ego assuming that all scientists must be just like him.