And if the information were really THAT sensitive, Israel would have given another reason for his dismissal, or even called the dismissal a "promotion" or "lateral occupational move." This reeks of a smear campaign. Maybe he leaned a little too much to the left for the status quo in the Israeli Administration...
Bennett, Deri expected to resign from Knesset, remain in cabinet under new 'Norwegian Law’ (Haaretz)
from the article: Official at Israel's U.S. embassy dismissed for leaking sensitive info