I'm pretty inclined to accept whatever JD-EE (female) says about electrical matters and the production of ozone. However I suspect many of us will not be able to reliably distinguish the smell of ozone from the smell of an electrical fault/short. A common misconception is that the this "electrical smell" is a result of ozone production. So did the pilots really smell ozone, or did they smell an electrical problem that they (incorrectly) ascribed to ozone? What may be easily distinctive to JD-EE may not be to many of us.
The timing seems suspicious, and I would not be inclined to dismiss an electrical fault just because this fault should not have produced ozone. It might have produced something that the pilots believed was ozone.
At the same time that both pilots suddenly perceived that the cockpit had suddenly become uncomfortably warm. A sudden updraft of warmer air from below, which was sufficiently rapid to temporarily "overwhelm" the ability of the climate control system to compensate? Maybe. Or maybe something else.