I'm in the jury of a PhD thesis in a small institution in Canada. The candidate has been a part-time PhD student here for about ten years, and is also the founder of a not-for-profit that aims to disseminate the results of his research. Apparently, he received a MPhil degree from the University of Cambridge in 1986. I've seen no indication on his web site or anywhere else that he has any continued relationship with that institution.
Now (2022), he will present some of his current PhD research in a workshop, where he listed his affiliation as University of Cambridge.
To me this looks very dishonest: he should claim affiliation either with our university, or with his not-for-profit organisation. I suspect a fancier institution might have been a way of sounding more important and improving his chances of acceptance (this was just a paper proposal based on an abstract, not blind peer review).
Question: Is there any "rule" that says which institution you can claim affiliation with? Is this just bad form or clear academic dishonesty?
Secondly: I have a feeling that there is some misbehaviour here, but should I allow that to affect the evaluation of the thesis? (I mean, after follow-up and checking what the situation actually is)
Update: The thesis supervisor indicated that the Cambridge affiliation was used to obtain a participation grant, which was only available to members of certain universities. The conference people apparently thought it was ok to use his alumnus status as affiliation.