"MI5 and counter-terrorism policing got a great deal right - particularly in the case of Manchester, they could have succeeded had the cards fallen differently", Anderson said.
Two pieces of intelligence were dismissed as "not terror-related" in the run-up to the attack, and MI5 missed the chance to issue a notice that would have triggered an alert when the bomber, Salman Abedi, re-entered the United Kingdom from Libya four days before the bombing, says The Independent.
The report looked at how Britain's top security agency, MI5, and police, handled the four terror attacks in Britain between March and June of this year.
Abedi, a 22-year-old Briton born to Libyan parents, detonated explosives following a concert by USA singer Ariana Grande.
"[The investigation] continued to varying degrees until the day of the attack, it did not reveal the plans or Khuram Butt and his two co-conspirators", read the report.
It was reopened in 2015 on mistaken intelligence that he had contacted an ISIS figure in Libya.
"It is not the objective of the internal reviews, or of this report, to cast or apportion blame".
Suicide bomber at Manchester's arena 'could have been stopped'
In the run-up to the May 22 attack, intelligence was received that was "assessed at the time to relate not to terrorism, but to possible non-nefarious activity or to criminality".
The review found that Abedi was one of a small group of former suspects of interest whom Britain's security services were considering investigating further. The attack at Parsons Green, on 15 September, was not covered by the report.
Abedi could have been stopped had MI5 interpreted two key bits of intelligence differently according to the findings of Ex-counter terror chief David Anderson.
The shadow home secretary, Labour's Diane Abbott, meanwhile has expressed concern that Abedi had not been under active investigation by MI5.
Butt was the "principal subject" of an MI5 probe called Operation Hawthorn that "opened in mid-2015 following information suggesting that he aspired to conduct an attack on the United Kingdom", according to the Telegraph.
It also was disclosed that Masood, 52, had watched suicide attack videos on YouTube in the days before he mowed down pedestrians on March 22, killing four, and then stabbed a cop to death.
Honor 7X: All you need to know about the upcoming smartphone
From what we gather, the Chinese phone will run on Huawei's self-developed OS EMUI 5.1 which is based on Android 7.0 Nougat . You'll be able to pre-order the Honor 7X in blue or black beginning today for $199, and pre-orders end on December 14.