I don't know if it's true, it probably isn't: the italian judicial system is almost "obliged" to take into account proposal of these kinds. Looking at another article, we can see that
thus, in light of my knowledge of italian society, this is how i would interpret the news:and were probed by L'Aquila prosecutors after members of the public complained that it was the committee's reassurances that persuaded them not to leave their homes ahead of the quake.
some dumb villagers of Abruzzo that don't understand anything mildly scientific read something about earthquakes on a newspaper, but didn't really consider leaving their homes. After they were struck by the earthquake, their idiotic attitude told them they need to find a scapegoat; thus, a local stupid politician decided that the head of the earthquake monitoring institute might be the easiest target. Prosecutors are forced to put him on a trial, which will end in nothing.