yup, there is more than one version it seems. What sauce makes you so sure it WAS who you say it was?
I think that because (a) Hezbollah is the most powerful political force in Lebanon and it is unimaginable that so significant a decision could be made — to store a massive amount of explosives in that place - without their knowledge or consent and (b) they’re the only entity that could buy or make use of that large a quantity of explosives. The only other remotely possible alternative is the lebanese army, and they don’t need to store explosives like that. They are, at least nominally and in the eyes of the UN etc., a national army and they don’t have to even pretend to hide their weapons. Hezbollah, on the other hand, does hide weapons all over the country — often in civilians’ homes, in schools, mosques, etc.