They travel about 600 MPH, and the ship was ten miles off shore. Should hav had about one minute to acquire, track, engage and destroy. But if it came in low, they had less time.
Here's my initial, thought-out assessment:
The IDF had their high value AAW vessel there to protect its gun boats who were shelling the Lebannon shore. Those gun boats have a short range which means the Saar 5 had to be close in to shore to protect them. That allowed it to be targeted in an evironment which minimized it's defenses and maximized the C-802 capability.
They were too close to respond effectively or in enough time.
Israel needs longer ranged shore bombarment capability to avoid putting it's modern, sophisticated AAW vessels at such risk, and to give them more time to resspond to a modern SSM threat.
There are a couple of things about your analysis that I'm still mulling over.
- Unless the IDF had specific knowledge of munitions caches in that area, I don't know why they'd waste their time with shore bombardment at these early stages. Especially when air assets would have much more effective.
- Why waste an important AAW asset that to counter a threat that doesn't exist? For missile defese, you'd want your AAW down the threat vector of the asset you're trying to protect, not outside it.
My guess: The shelling was a diversion for SOF insertion. Hope they made it in.