That a phenomenon seems to be wholly explicable in natural terms does not, of course, mean that it is not due to an ingress of Divine Grace. Thinking so is a common error of the naturalist bent – or rather, what it is more accurate to say, of the bent naturalist. But natural explanations do not rule out supernatural explanations. There is, indeed there can be, no conflict between natura and supernatura; natural explanations are all in the final analysis also supernatural explanations, because natura presupposes supernatura.
After all, the whole system of natural causes upon which mundane phenomena supervene is itself supervenient upon, and continuously provided by, Divine Grace. You need Grace in order to get a world in the first place. Natura is a process of supernatura.
“There is no conflict between natura and supernatura.” But is there not a War in Heaven, and on Earth? Indeed. But the Adversary and all his minions, demonic or not, are both natural and supernatural. The conflict is not between natura and supernatura, but within both. Parts of both have Fallen. Parts of both now fail to achieve the beauties they might otherwise have enjoyed, had they never Fallen.
The corrigible defects of both shall be corrected at the eschaton, when Christ shall in the end be all in all. In that Day, Earth shall be at last again what she was first meant to be: a domain of Heaven, and all her citizens saints.