So the glitch prevented them from finding the fire quickly enough. That makes more sense.
Anyway, a cigarette butt could potentially be another cause, if people are sloppy, but I feel better believing it was a short circuit.
Well it's not out of the question that could be a cause too still, considering there was already a form of renovation going on there.
The only thing I can think of a use of a computer, at least in a place like old and huge, was an attempt to handle some building automation. Such as lighting control.
However, a computer isn't technically glitching when it does exactly what it was programmed to do, say turn light A on or turn on exhaust fan C... Like if there was a short circuit, or some old (or new can happen too) wiring got damaged during renovation work... or an old piece of air circulation equipment had an issue then it could be a failed safety circuit like a fuse or circuit breaker. Which a computer wouldn't be aware of in most cases, unless there is some sort of advanced feedback system installed.
Though another possibility that isn't uncommon is someone
bypassing safety measures, like replacing a fuse with a metal bolt, or hooking the electrical up direct.
One of the family friends we have used to do heat and air work, and one of the installs he did was at a church. Well, the furnaces were not running yet since the gas was still turned off, but yet somehow that church ended up burning to the ground shortly after. It turned out from investigations, the cause was due to someone outright bypassing a fuse within a circuit box that fed the emergency exit signs... the wire ran alll the way up to the steeple and then throughout the facility to feed every single exit sign. One of those ended up shorting out and with zero protection you had the full 200 amp services going into that 12AWG or 14AWG cable melting it down and thus causing a fire.
It's rather unfortunate, but many people tend to forget or don't simply care about the safeties put in place. With a place as old as that Cathedral, especially with as
huge as it was, who's to honestly say when it first had electricity installed, when or if it was ever upgraded to any partial or full extent, and how well it was maintained. Some maintenance people could easily have helped cause greater wear and tear on an electrical system of any age, like the incident mentioned above.
Maybe they'll determine the exact cause of the fire in this case for the Cathedral, because I'm sure it could be a lengthy investigation still if they are not 100% certain yet still.
It's just coming from our line of business and experiences from the folks I know of that seen such things done, too many people do things that just aren't safe. Plus there's still always the result of failed equipment causing the issue, but sometimes that can be made worse if safeties were removed from the equation.