Let's put it anyway we want. We all know how dangerous it is, and therefore forbidden to take off, to land, even flying near a Cb cloud, and we have at our disposal all means (folder meteo, wx radar, other traffic, air traffic control, etc..) To avoid it.
-Did they take off in the vicinity of a thunderstorm?
-Did they dump fuel (they were certainly above the maximum landing weight)?
-Was it a wise decision to return to landing rehearsing through the hell they came from?
If an inconvenience occurs more than once, it means that someone has to intervene in some way: on training?
But let's wait the report to be published.