One might assume that this supply chain attack was performed somewhere towards the end of the chain, near the end users Hezbollah.
However if the attack was performed earlier in the supply chain, then conceivably there could be other explosive laden pagers circulating out in the wild, yet to be triggered because they were not within broadcast range.
It seems prudent that the manufacturer issue a recall notice for their pagers, at least until Israel/Mossad admits liability, and informs the manufacturer at which point in the supply chain was penetrated.