First of all, note the headline. This has now become a "murder case?" Why the change? Previously the Huffington Post referred to it as a "killing" (see here and here). Did something change in the nature of the event to upgrade it to a murder? Or is there bias, and if so is it coming from the Associated Press or from the Huffington Post?
Anyway, the story is that Britain expelled an Israeli diplomat because they were mad about Israel's role in the forged passports. There is still nothing in the story to indicate that Israel was behind the assassination of Mahmoud Al-Mabhouh. See here:
"However, Miliband insisted Britain has drawn no conclusions over who is responsible for the killing of Hamas official Mahmoud al-Mabhouh, saying investigation by Dubai authorities was continuing."
Don't expect the readership of the Huffington Post to have read that far, though. Of course, most of them had made up their minds long before this decision was ever made. Right now the fully moderated talkback thread has about 500 comments.