You can determine if fire is arson if there is residue of an accelerant. SHC implies the body's own heat source causes the body to attain such high temperatures that the body catches alight, and the body burns to ash just as if it were burnt by an external source. The organic chemicals in the body would be broken down if SHC happened and the chemicals would be synonymous as if the person were burnt by an external source. This is just common sense, try catching something alight with radiowaves (not advised) and catch the same type of objects alight with an open flame. A person who didn't see what happened wouldn't be able to tell if the object caught alight from the radiowaves or from a simple open flame. No one has bothered to look at the episode for themselves or even pose a good argument against Frank Baker's story aside from ''a lack of evidence'' but really you have to understand SHC is something that, even if it exists, you wouldn't be able to find evidence for anyway, at least not scientific evidence, more like witness testimony and pictures, since the evidence literally gets burnt away so there is no evidence that SHC occurred despite the circumstances being incredibly unusual, and people don't just simply burst into flames without an external source, unless there is an internal source of heat being responsible. We also cannot say that the person is lying and there's some huge conspiracy of SHC either. Occam's Razor points towards SHC being a malfunction of the body instead of a mass conspiracy of people who are all making up the same experience. There are simply too many cases to dismiss all of these as liars, and there's the problem of people opening up about something so strange, risking public ridicule when they could just lie about something mainstream science bothers to accept because it can be tested in a lab as it happens.