I think it is considered terrorism. Whoever did it, nobody would say that this attack makes military sense, lebanon is not at war, and civilians have died. But since IDF didn't do it, we ll never know who the terrorists are.
even though incidents happened on both sides, neither side has started an 'active war' against the other. plus, we don't know who tampered with those devices
Hezbollah has been firing rockets at Israel, how more active does it need to get? The notion that Israel just need to take it and can't go after the organization that conducts such attacks is absurd.