Did Fatah or PA have a Role in Dubai?

I don't like to spread what may be totally scurrilous rumors, but on the margins of the videorecorded hit against Hamas figure Mahmud al-Mabhouh in Dubai, a classic targeted assassination that looks to almost everyone (including the UK, Ireland, Dubai, and as far as I can tell most of the Israeli media) like a Mossad operation, there was the arrest of two Palestinians in Dubai for some sort of connection with the apparent hit squad. Not too surprisingly, Hamas is claiming the Palestinian Authority/Fatah cooperated with the Israelis in the hit.

There are, of course, a lot of Palestinians who have no connection to either Hamas or Fatah, but the traditional conspiracy-theory-prone mindset of the many in the region (and some of us who just study it, for that matter) means that seems almost credible. But it doesn't help move things forward, does it?