Thanks again Radgirl, that clarifies things.
Even if what I experienced could genuinely be described as deluded thought, given that it was a one-off transient response to some of the most extreme stress I had ever experienced, am I right in understanding it shouldn't be an obstacle to certification? The CAA guidance material on psychiatry states the following:
Class 1
(d) Schizophrenia, schizotypal or delusional disorder
Applicants with an established schizophrenia, schizotypal or delusional disorder should only be considered for a fit assessment if the licensing authority concludes that the original diagnosis was inappropriate or inaccurate or, in the case of a single episode of delirium, provided that the applicant has suffered no permanent impairment.
I can recount only one extreme example of obsessive compulsive behaviour which could possibly be described as delusional and it was the single instance referred to briefly by the aforementioned report. As far as I can tell from my amateur understanding of the definition it could be described as a delirium - so shouldn't it be possible to work around it given it happened once only? I can recall only one instance of it being that bad and can find only one example in my medical reports (I had to source from my GP and submit to the CAA my entire medical records, so I still have copies of everything).
The CAA say in their letter I have a "history of deluded thought", but I cannot understand if they consider the one instance of it to qualify as a "history" or if they seem to believe there are multiple occurrences. I guess the above GM is a starting point though so would appreciate any feedback on whether or not I've understood it correctly!