That seems probable. There hasn't been extensive coverage of this in English to my knowledge, but the profile of the bombers really does not make them out to be mastermind terrorists of Muhammad Atta caliber. I did a story for The Times reporting the basic facts, but it got cut down a fair amount. I'm reproducing the relevant excerpts below:
The [interior ministry] statement identified Ayad Said Saleh, a Palestinian living in the northern Sinai town of Al Arish, as the mastermind behind the operation. Saleh and one of his accomplices, Suleiman Ahmed Saleh Flayfil, were killed as they tried to escape the bombing scene but were caught by the explosion, suggesting that the bomb timers had malfunctioned and that the attacks were not intended to be suicide bombings.
“This confirmed that the incident was not a suicide bombing operation as the Palestinian and Egyptian were killed as they escape from their vehicles after they had failed to set the timers properly,” the statement said.
The two men were identified through DNA samples taken from body parts found on the scene of the bombing, it added.
Two other men who participated in the operation – Flayfil’s brother Muhammad and Hamid Jumaan Jumaa Jumaan – are still at large.
Investigations have also led to the arrest of five men – most of them Sinai Bedouins from Al Arish – who, while not directly involved in the bombings, participated in their preparation.
The ministry of interior said that several of the men who were arrested owned or worked in small workshops were the put the bombs together with unexploded ammunition from wars fought between Egypt and Israel in Sinai. These were rigged to timers recuperated from washing machines and placed in vehicles that were stolen for the operation by a one of the men, who was a known stolen car dealer.
Another one of the men arrested, a Bedouin from the area where the bombings occurred who owned a holiday camp, provided information to the bombers on the resorts that were targeted.
Saleh, the alleged mastermind, worked as a driver, had a long criminal record, and was most recently involved in the rape of a young woman in his car. The statement said he had “recently become a religious extremist.”
“[The attacks] were a response to the breakdown in the situation in the Occupied Territories and was targeted at Israelis staying in the hotel and the two holiday camps,” the statement said.
The statement however did not mention whether the nine men were part of any organisation. Three groups have claimed responsibility for the bombings, including Al Jamaa Islamiya Al Alamiya (the International Islamic Group), Kataib Al Tawhid Al Islamiya (the Islamic Brigades of Belief in the Unity of God), and the Abdullah Azzam Brigades. The last of these groups, named after a leading Islamist activist, was previously unknown but has repeatedly claimed responsibility for the attacks in the Arabic-language press and may be affiliated with Al Qaeda.
Overall, the bombers -- if this is them, which some people doubt considering the extent of the damage caused by the bombings in heavily policed area -- don't really seem like Al Qaeda types. Petty criminals turned radical, perhaps. And the fact that they used old unexploded ordnance and washing machine timers doesn't inspire much confidence, either.
Incidentally, a friend of mine who works at a local human rights organization has told me that there were massive arrests in Sinai during the investigation -- and a lot of torture and brutality against innocent civilians. His research will probably make it out as a report soon, but it's a reminder that these attacks only tend to worsen the already rather dire impunity with which police and security services operate in Egypt.