It's the CIA agents at the US Embassy in Beirut and the American electronic equipment supplied to Lebanon that were responsibe for detecting the Israeli agents. US is eager to cooperate with Hezbollah ,despite death of 200 US Marines in Beirut bombing ,murder of the local CIA -chef (skinned alive ) or murder of an US Marine aboard the American plane kidnapped to Beirut by militia associated with Nabib Berri ,still serving in the Leb Goverment. Agent escape proves Israeli Intelligence got smarter and doesn't trust its American counterpart.
Israeli forces demolish illegal houses, power infrastructure in Palestinian village Aqaba (Haaretz)
from the article: Report: Suspected spy for Israel escapes from Lebanon