No it wouldn't but I would also say a Petrol car cannot be the cause of a fire. Likewise I would also say an battery power car is not the cause of a fire.
Now if you said which vehicles were at higher risk of catching fire then that is completely different and would agree that EV's are safer in that regard but at the same time if you said which fire would be easier to put out then it would be a bit different.
Right.
So what you are describing is a set of conditions that only applies to a diesel engine.
By the way what you attempted to do was the "5 whys" approach to simple root cause analysis.
Its really not a full blown root cause analysis as such but to give you a head start on what to look into.
Really in this situation with what we know now it would be :
Statement/problem : There was a car fire.
Why 1: Why?
Answer 1 : We don't know.
I think your getting a bit confused on the specifics of cause here. The car needs to be considered as a whole.
Why was there a fire? One or more of the components of the package "the diesel car" failed and triggered a fire.
The point of root cause analysis is to identify the issue and try to solve it.
Working in manufacturing where there is high risk, you always look for 2 things, point of failure (such as no grounding) and fuel source. You need both.
A spark is not an issue if there is no fuel. A fuel spill is no issue if there is no ignition source. But the two together are a problem.
So you try to ensure no ignition source near any fuel sources, and no fuel source near any ignition source.
Our FLTs for example are all modified to comply with ATEX. Its practically impossible for them to generate a spark on failure.