It doesn't matter who.
There seemed like an unwilling for Hezbollah to get involved and right now, NY Times is reporting that Iran was taken by surprise about the Hamas attack last Saturday. Hezbollah won't move without Iran prodding. So Hezbollah either directly or allowed some Palestinians groups to fire some rockets on Shebaa Farms as a token of 'solidarity' with Palestinians. It was just a token gesture but Israelis, in their eternal usual arrogance, killed several Hezbollah fighters in response. And we see now what we see.