I found myself thinking "this dude seems autistic", and I felt guilty for such a thought, because being autistic myself doesn't render me immune from projecting problematic notions onto other people (autistic or otherwise). However, my thoughts went there because I've seen this kind of single minded obsessiveness manifest for good or for ill across many different people.
I remember one time discussing the grim state of the world with a friend, who quipped "man, I'm glad I'm autistic, because I'd have probably topped myself if I didn't get this level of obsessive joy from my train set". Similarly, I have friends who have made their special interests into their career (which certainly can go wrong, due to inability to "switch off", and decreased life compartmentalisation). It is sometimes hard to find a healthy balance when some people genuinely do thrive in revelling in their obsessions.
As it turns out, the dude in the article is autistic — it sounds like maybe the diagnosis happened after this incident, so at least something good came of this. Maybe it's a pipe dream, given that support for adults with autism can be pretty grim, but I hope he's able to find the support to chase his passion in a manner that's healthy and fulfilling for him. My nerdy interests have never driven me to things like arson, but that doesn't mean I don't relate to that level of intensity