As I understand it, the reason that the case you are talking about where the Jewish American was shot by Palestinian Authority police was not dismissed is that the court ruled that the PA was not a sovereign state, so its agents were not entitled to immunity from suit. Also, even if the PA were a state, the gunmen in that case were probably acting outside the scope of authority. In other words, if Avi Dichter was Shin Bet director by day, and part of a street gang that did drive-by shootings at night, the drive-bys would be beyond the scope of foreign immunity. But the official military policy of foreign states is not generally something you can sue for damages in U.S. courts for--or our courts would be very busy with trials of practically every military action in the world.
In Bahrain, 2 police officers killed, 6 wounded in bombing (AP)
from the article: U.S. District Court in Manhattan clears Dichter in war crimes suit