There is no doubt that Israel pursues a policy of extra-territorial assassination of its enemies. All responses to this story that refer to inadequate evidence are, therefore, beside the point. Even if, by some remote possibility, Mossad wasn't responsible in this case it is clear that they would have killed the guy if they could have done. Netanyahu presumably has some knowledge and oversight of Mossad activity. It is therefore reasonable for Dubai to seek his extradition if they have some evidence of Mossad involvement.
German accused of joining ISIS in Syria deported by Turkey (AP)
from the article: Dubai seeks Netanyahu's arrest over killing of Hamas man