A police officer shot during a 17-hour armed siege would probably be dead if he had not been wearing body armour, investigators have said.
Pc Lomas, a local community beat manager, joined the force in 2001
Pc David Lomas recovered from serious injuries he suffered in Rawtenstall, Lancashire, and has returned to duty.
On Thursday, the police watchdog said "perhaps the time had come" for all officers to wear armour.
Pc Lomas opted to wear his armour for what he thought would be a "routine arrest" in July 2005.
The gunman, 54-year-old Stephen Hensby, shot Pc Lomas with a shotgun and then hurled petrol bombs out of an upstairs window.
The officer was pulled to safety by a colleague and airlifted to hospital with a shoulder injury.
Officers stormed the house after nearly 20 hours to find the gunman and his Rottweiler dog dead in an upstairs bedroom.
On Thursday, the Independent Police Complaints Commission (IPCC) said Pc Lomas' decision to wear armour may well have saved his life.
Mike Franklin, IPCC commissioner for the North West, said he and the other officer who attended the house that day had been confronted with a "totally unexpected level of violence".
"If Pc Lomas had not donned his armour in this instance we may well have been investigating the death of an officer," he said.
"Historically, officers do not have to don body armour unless they feel they are in danger.
"But the level of, often unpredictable, violence now faced by police officers means that perhaps the time has come for officers to always wear body armour unless there is good reason not to.
"Our investigation report suggested this as a change of policy for Lancashire Constabulary to consider."
Pc Lomas, a community beat manager, and colleagues had been sent to the house to arrest Hensby after an allegation of harassment and anti-social behaviour.
The IPCC's report said the officers had acted "with total professionalism throughout" and suggested several be put forward for commendations.