That was an Argentinian court so I'm not sure the government matters. Also there is other evidence of Iran's involvement. Not to mention countless other attacks on Israel proper and Israelis.

I don't think it's clear from an international law perspective. I remember reading the Vienna Convention and not really finding anything specific and my attempts to read it now and use AI to figure it out aren't yielding anything.

The status of the embassy or consulate is generally considered to be an agreement between the host and guest countries. It is not considered territory of the sending country at all.

Anyways, as we said this is mostly splitting hairs. Israel had really no grievance with Iran and no reason to act or attack it before Iran decided that destroying Israel is one of its goals. In the kindergarten game of "who started" it was clearly Iran, no doubt about that.