No, he might said he is atheist, and probably he even believed it himself, but did you even read any of his books? He loudly denounced this or that god, but everything was just oozing with the essence of agnostic seeking new spiritual opium. At the point he defended evolution theory with truly neophyte zeal (i’m saying about how he presented it) so when he clicked back to his old opium, just with the meaningless “cultural” addition, it wasn’t surprising at all.