Yep that is it. You see on Flightradar and the airport site that other arriving flights were diverted or delayed too around that time, e.g. ZRH-SJO diverted to Liberia
https://www.flightstats.com/v2/flight-tracker/arrivals/SJO/?year=2019&month=9&date=6&hour=12
https://www.flightradar24.com/data/f.../wk36#21fe4199
The Edelweiss flight managed to land in SJO in the end around 20 pm (as opposed to the 18 pm scheduled local time), and while this led to a delayed return flight, in the end the damage in ZRH was just one hour. Much less disruptive for passengers and flight operations as the solution used by AF430 - but then, they will have had good reasons to choose PTY as diversion.
https://www.flightradar24.com/data/aircraft/hb-jmd