There's no particular downside to the Israelis from this hit (other than a few Mossad operatives whose photos have now been circulated). It sends a message, possibly prods Hamas into a poetentially self-destructive mole-hunt, removes an effective operative, and pays off well domestically.

Had they botched it--as they did in Lillehammer in 1973, Amman in 1997, or Auckland in 2004 it would have been a different matter. Also, unlike the Mishal assassination attempt in Jordan, I don't think Israeli relations with Dubai/UAE are of particular concern to the Netanyahu government (although Wilf might want to be careful next time he's traveling to or via the Gulf!)