I have to admit I do have to try and stop my own biases with it being as far as I am concerned a fluffy-role, was his publication record thin for that type of role, I sincerely have no idea?
Multiple people in that field have come forward to say that they realised at the time that his publication record was pathetic for a job of that nature. They didn't say anything at the time of course, for fear of accusations of racism.
A strong publication record, both as regards numbers and depth, is the main thing an appointments committee will look at. That and the ability to attract research funding, and having headed up major research projects. (Teaching ability is a fair way down the list, at least as regards undergraduates. They will be expected to have supervised many PhD students through to graduation though. Arday hadn't done a single one.)
I remember when one of my PhD supervisors was promoted to Senior Lecturer. I had by then realised that he was a bit of an intellectual lightweight, and was being carried along by being able to talk a good line, and by the efforts of his numerous PhD students whose work he assimilated. He got them to write papers, which was good for their CVs of course and their academic development, but then he got his name on all the papers. Heard in the tea-room later, "Well have you seen his publications list? It ran to five pages. All they did was count the papers and give the job to the guy with the largest number." He wasn't useless, but I relied more on my other supervisor, he just wasn't a heavyweight. He left for another job where they saw through him and he was sacked. I later went up to his former boss at a BVA meeting and said, I just want to shake the hand of the man who sacked David Snow!
For a senior professorial chair, particularly when considering an unusually young candidate, the appointments committee should be taking a very deep dive into his work I would also expect some informal conversations with people the candidate had
not named as referees but had worked alongside or under him.
By all accounts, in addition to his PhD being plagiarised "quotes" linked together by meaningless waffle, his publications were few in number and lightweight, some merely detailing a handful of conversations he'd had with people, or even with a friend. These also showed both external and internal plagiarism, copying from various other sources and then repeating the same material from paper to paper. If you listen to David Harris's video, this was what he first noticed. He was writing a book about the subject, and when it was nearly completed someone drew his attention to the existence of Jason Arday, whom he had literally never heard of. He felt this was a serious omission, and started to skim-read Arday's papers to get a handle on his research. Reading them one after another like that he spotted the same quotes being attributed to different subjects in different papers, and other anomalies and inconsistencies.
If David Harris could do it, the appointments committee could do it.