A health watchdog will determine whether an apology from hospital bosses was enough after they admitted failures.
United Lincolnshire Hospitals Trust (ULHT) apologised to Ralph Bryant, 78, from Doddington Park, Lincoln, after he was not told about his wife Marjorie's cancer diagnosis for several days. Staff at Lincoln County Hospital also delayed in telling him his wife had suffered a heart attack.
Mrs Bryant, 80, died on November 28, 2009, a few weeks after she was discharged.
The trust admitted failures including a lack of communication and in discharge arrangements.
An internal investigation found these shortcomings did not amount to a failure in its duty of care. It is understood the Parliamentary and Health Service Ombudsman will now begin a formal investigation.
This will look at whether ULHT's investigation of Mr Bryant's complaint failed to find a remedy for the failure in providing timely information to the Bryants; inadequacies in the discharge system meaning Mrs Bryant was left waiting alone in her dressing gown in the discharge ward and inadequate nursing assessments.
Mr Bryant, who now lives in Kent, said: "I am seeking assurances that the hospital is doing things better. That's got to be good for other patients and other families.
"Even though they apologised, they still let my wife down. They admitted they made mistakes but they said they did not think they failed in the standard of care."
Businessman Darren Fernie, the Bryants' former neighbour, is championing the case.
"For Ralph and myself the concern is that the hospital already had processes in place which should have resolved problems and not allowed issues to arise," he said.
"The ombudsman has heard back from the hospital and the investigator agrees that the replies are inadequate."
In October 2011 the trust provided the ombudsman with an action plan following an investigation into an unrelated complaint. A revised complaints system is now in place which aims to respond within an agreed timescale.
The ombudsman will consider comments from the trust and other evidence before making a decision on whether to proceed with a formal investigation.
ULHT spokesman Becky Derbyshire said: "We would like to apologise to the family of Mrs Bryant for problems in communication with them about her medical condition.
"We are aware that the Parliamentary and Health Service Ombudsman is investigating this case but cannot comment further at this time."