Right. Moreover, of all the people who read GabrielDuquette's comment and know someone that had cancer and went to a faith healer, I imagine only the ones with a story like Jayson_Virisimo's will post a reply. Failed attempts are not reported. If you are acquaintances with someone that experienced a failed faith healing, you are likely not even aware of it! (If it was successful, they would have lauded it.) An easy Bayesian estimate makes the presence of Jayson_Virisimo's comment unsurprising.

Given a sufficiently non-zero probability of spontaneous remission, this argument explains my lack of surprise at such a story. This is an important addition to your argument (and, I feel, indeed the crux), because a non-zero probability is not satisfactory. Consider if we had many people posting such claims; with sufficiently low probabilities of spontaneous remission, we would not expect such a density of claims.