Did you read the article? It has confirmation by U.S. sources.
All I see really is a Haaretz tabloid-ish piece citing unnamed sources and noting a Congressman visiting Beirut to investigate an earlier case. This story is a swiss-cheese mess of innuendo.
Note the LA Times story on the Beirut mess;
http://articles.latimes.com/2011/nov/20/world/la-fg-cia-spy-20111121
Informants. Not agents. The Iranian mullahs either got lucky and stumbled on the same or just hit up some poor university students who didn’t chant “death to America!” as quickly as they were expected to.