Perhaps the "technical error" was a weakness in their security which was exploited by another party???
Or maybe it is just a fundamental lack of training. Of course if they go and train it a) uses up resources / ordnance, b) other parties tend to notice said training and take interest in the participants, their locations, etc.
So, if the Israeli intelligence “knows about” a arms depot in Lebanon, how it is possible the (legitimate) Lebanese government “does not know” about it?
No sympathies for the neighborhood - The weapons stored inside were being used against innocents elsewhere.