This is ONLY my experience, but may be relevant, or probably won't...
Degree educated, good at the job, but one colleague in particular has this way of talking about such obscure things, in away that implies common knowledge. I seem to constantly be saying "umm I don't know what you mean ". He uses vocabulary not muttered since Charles Dickens era and he has a general air of competence.
So for years and years I had to accept that I was a moronic minion to his majesty. But then I got dumped with 8 of his cases, all late, all maladministered, all totally incompetent
What I learnt and what fits the scenario you describe in my opinion, is that HE felt intimidated by ME and was projecting this on to me by covert means.
Now, if you are high up on this pedestal and he is your average guy, he MAY feel that he needs to prove that he is not inferior...to your detriment.
OR he could be a highly gifted intellectual ...such people do not tend to use fancy words...they do not need to