Why did this aircraft take off in the opposite direction compared to the one used by other flights right before/after it? I recently took a weekend trip to Naples and went to admire the city from above at the Certosa di San Martino panoramic viewpoint which, it turned out, was also offering a distant view at NAP operations that morning (June 15, 2019, around 12PM CEST). After taking a few pictures I couldn't help but spending a good 15 minutes tracking a few landings and departures with the FlightRadar app.

Runway 24 was in use at that time, except for a single departure in that timeframe which used runway 6.

Is this a common scenario - i.e. a single aircraft taking off from the runway opposite to the one currently in use?

I know the general factors taken into account when determining in which direction a runway is used, but what could be the reasons behind such a sudden and isolate (takeoffs and landings just 3 minutes before/after used runway 24) change in the airport operations?

The aircraft in question left NAP with more than 1 hour delay, leading me to think that it could have been pilot's request to spare a few minutes: probably positioning for 6 was faster from their gate?
It looks like the reason for the Rwy 6 departure was noise abatement. The climb gradient from 6 is not as steep as for 24. The Jeppesen charts state the requirements:



And it states that if you are unable to comply with the steeper noise abatement climb gradient for rwy 24 (583 ft climb per nautical mile), you should request 6 (300 ft climb per nautical mile). Maybe the plane was fully loaded and the captain wanted to avoid a fine.