Shana's own footage showed the tank used deadly force without any warning
Reuters news agency says the Israeli army has made reporting in Gaza "almost impossible" after it cleared a tank crew that killed one of its cameramen.
Fadel Shana and eight other Palestinian civilians, mostly children, were killed by a shell packed with darts in April.
The army's top lawyer said the troops acted properly as they suspected his camera tripod was an anti-tank weapon.
Reuters says it shows the army is not meeting an obligation to protect civilians in combat areas.
Shana was filming some Israeli tanks from about a mile (1.5km) away on 16 April when one of them fired a flechette shell, an anti-personnel weapon which releases a shower of darts.
Nine people were killed, including Shana and eight young Palestinians, all unarmed, aged between 12 and 20.
The incident, which Shana caught on film before his death, shows the tanks fired no warning shots and there was no other fighting.
"The army itself admits that they could not tell whether they were looking at a camera on a tripod or an anti-tank missile system on a tripod," Reuters Jerusalem bureau chief Alistair Macdonald told the BBC.
Although there is no record of Palestinian militants using such a system before, Mr Macdonald says, the tank used "devastating force with a weapon that is designed to kill as many people as possible" in a wide area.
In the previous half-hour Shana's car, marked with TV and Press stickers, had driven within 700 metres of the tanks, Mr Macdonald said.
Israeli officials have called the incident a tragedy but insist it had not been possible to identify Shana and his soundman, who was also wounded in the incident, as journalists.
"In light of the reasonable conclusion reached by the tank crew and its superiors that the characters were hostile and were carrying an object most likely to be a weapon, the decision to fire at the targets... was sound," military advocate-general Avihai Mendelbit wrote to Reuters.
Earlier on the same day, three Israeli soldiers had been killed by Palestinian militants and there had been a grenade attack against a tank, the lawyer said.
"The tank crew was unable to determine the nature of the object mounted on the tripod and positively identify it as an anti-tank missile, a mortar or a television camera," he wrote.
Mr Macdonald called the ruling "very disappointing" on two levels, because the journalists had been identifiable and because the Israeli army admitted it was not sure whether they were militants or civilians.
The Israeli army found that its soldiers' decision to fire had been 'sound'
"This policy to shoot first if there is the slightest doubt has rendered it almost impossible for us to do our jobs in Gaza along with the rest of the international media," he told the BBC's Today programme.
He also accused Israel of not co-operating with the media to improve journalists's safety in Gaza.
Journalists in crossfire
Government spokesman Mark Regev said Israel understood the role of an independent, free press in a free society.
"These are situations that are faced internationally and we have got to find a better way to try to make sure journalists are not caught up in crossfire," he told the BBC.
Committee to Protect Journalists representative Joel Campagna said: "These findings mean that a journalist with a camera is at risk of coming under fire and there's not that much that can be done. That's unacceptable."
The CPJ says at least eight journalists have been killed in the West Bank and Gaza since 2001, seven of them were killed in attacks by Israeli army.