Is it to deflect attention from themselves? According to a report in the Daily Mail (via YNet) the UK knew in advance that the hit was taking place- and that UK passports were being used.
The Daily Mail reported that MI6 was tipped off that Israeli agents were going to carry out an 'overseas operation' using fake British passports. The newspaper quoted a member of Mossad, the Israeli intelligence service, as saying that the Foreign Office was also told hours before the Hamas terrorist chief was assassinated in Dubai, although the tip-off did not say who the target would be or even where the hit squad would be in action.
A British security source, who met the Mossad agent and has a track record of providing reliable information, told the Daily Mail: "This is a serving member of Israeli intelligence. He says the British government was told very, very briefly before the operation what was going to happen.
"There was no British involvement and they didn't know the name of the target. But they were told these people were travelling on UK passports," he added.
The security source said the tip-off was not a request for permission to use British passports but more a "courtesy call" to let the security services know "a situation" might blow up. The Mossad man said Israeli intelligence chiefs understand British authorities will have to "slap them on the wrist".
Me thinks the lady doth protest too much. [sic]