I would hesitate to call it terrorism, it was targeted at military persons with an intent at military disruption and any public casualties were collateral damage. It may have been a war crime though.
Sabotaging dual-use communications devices that are used, specifically, by members of an enemy paramilitary group is not a clear-cut war crime. On the other hand, there is a very strong argument that 'blind-firing' such devices en-masse without regard for the proximity of civilians or possibility of civilian harm is a war crime via insufficiently discerning use of force. But even that is something that could probably be argued in a legitimately-unbiased international court - not that it'll ever fucking get to one, considering Israel's history with international courts.
Either way, it's a shite move that was only meant to escalate the situation so Bibi can stay in power a few more minutes. Vile shit.
"stress that booby-traps associated with objects in normal civilian daily use are prohibited, and that booby-traps must not be used in association with protected persons, protected objects (such as medical supplies, gravesites and cultural or religious property) or internationally recognized protective emblems or signs (such as the red cross and red crescent).[3] Several manuals further specify that booby-traps must not be used in connection with certain objects likely to attract civilians, such as children’s toys."
A cell phone is a normal civil daily use item and would attract use by civilians.
Hezbollah isn't just a paramilitary group, though, it's an actual political party in Lebanon.
You'd have to have an extremely narrow understanding of who Hezbollah even is to claim the attack was legitimate
Not to mention the intentional fear the strike created that now legitimizes Hezbollah's mandate against Israel. Yea, it was 'shite', but it seems pretty well designed to manufacture fear and chaos and to bait Lebanon into a broader conflict.
The disguising of a military weapons in the form of common civilian used equipment to trick your opponent is a war crime.
It was a war crime in 2008 when a bomb was disguised as a spare tire in an SUV used to kill the head of Hezbollah’s international operations, whether we agree the target needed to be taken out or not. A drone strike would be "lawful" a car bomb is not.
A cell phone is common civilian equipment. This isn't "whatever I think."