whether the assassins were israeli or not, the timing of his murder was based entirely on HIS visit to dubai and on opportunity. for the landau visit to have been connected with his murder, knowledge of his intended visit to dubai at the time he did would have had to be known by the israelis well in advance...which isn't very likely. and actually, if indeed the killers WERE israeli agents, the timing of their opportunity with the landau visit would be a less than desired coincidence because of its implications.
Stabbing reported in Kiryat Gat in southern Israel (Haaretz)
from the article: Dubai not ruling out Mossad hand in murder of Hamas official