The incident, which has made international headlines, drew howls of outrage from provincial politicians.
Progressive Conservative Leader Tim Hudak called it "outrageous" the 82-year-old woman would be treated that way.
"That a senior citizen would be left in a hallway at a hospital, while they said paramedics had to be summoned from outside the jurisdiction for half an hour?" Hudak fumed.
"We're in ... Ontario. This is the way you're going to treat a senior citizen? It's wrong."
Doreen Wallace's family says they were told an ambulance would have to be called after she broke her hip and cut her arm when she fell inside the doors of the Greater Niagara General Hospital earlier this month.
An ambulance was called, but by the time it arrived half an hour later, a passing surgeon had given her care.
Representatives from the Niagara Health System said it's still unclear who made the 911 call from the hospital, or whether hospital staff issued those instructions.
They said three staff members did go to her aid, including an off-duty nurse.
However, hospital leaders acknowledged proper procedure wasn't followed in Wallace's case.
They also said similar incidents occurred at the same hospital in recent months in which patients who needed assistance just outside the walls were also told to call an ambulance for help.
"This case was crystal clear: inside of our four walls, one never calls an ambulance," said Kevin Smith, a supervisor appointed by the government in August to oversee the embattled health system.
"The fact that someone made an error, it was just that: an error and errors happen. But the fact that the error has occurred on more than one occasion, without correction, concerns us deeply about process and structure and communication and accountability."
Smith said he spoke to Wallace, who was visiting her dying husband, on Wednesday and she seems to be "doing as well as expected."
The Niagara Health System has apologized to the family.
The hospital authority said it will focus on a quick response and transport to the most appropriate clinical setting in the future and do a review to find out what happened.
There no plans to fire any staff, Smith said.
Health Minister Deb Matthews was unavailable to speak with reporters Wednesday, but said in a statement she was "disappointed" by the "regrettable situation."
"I hope the findings of that review help ensure that what happened to Doreen Wallace doesn't happen again," she said in an email.
Still, questions linger about why such incidents keep occurring at the hospital.
In July, the husband of a Niagara Falls councillor sought help for his barely conscious wife, who was in the hospital parking lot. He said he was told to call an ambulance.
In April, Charlie Poisson, 45, drove his ill girlfriend to the hospital, only to be told when he rushed into the emergency department that paramedics would be dispatched.
When no paramedics came after about three to five minutes, Jennifer James, 39, was taken inside in a wheelchair and received care.
She died five days after being admitted, apparently of a "catastrophic heart event."
Newly elected New Democrat Cindy Forster, who represents the southern Ontario riding of Welland, said many local residents have lost faith in their hospitals.
"Clearly there is a huge lack of confidence about the Niagara Health System for people who live in the cities that are serviced by the Niagara Health System," she said.
"And I always say that confidence and trust happens at the front door of each one of those sites of the Niagara Health System."
The governing Liberals appointed Smith to the health system — the largest in Ontario — after it came under fire for a dangerous outbreak of C. difficile. It comprises six hospital sites and one ambulatory care centre.
Note to readers: This is a corrected story. An earlier version reported that Wallace broke her leg instead of her hip.