Alzheimer's sufferer Ken Godward, 76, and cancer patient Roger Lamb, 79, died after they were beaten by 70-year-old Harry Bosomworth with a walking stick at St James's University
Hospital in Leeds on February 28 2015.
Dr Susanna Waddingham told an inquest into Mr Godward and Mr Lamb's deaths that when she saw mentally ill cancer patient Mr Bosomworth on February 23 he was drowsy, confused
and, in her view, was delirious.
Dr Waddingham told Wakefield Coroner's Court there were no grounds at that time to have Mr Bosomworth sectioned under the Mental Health Act.
Dr Waddingham, who works for the Leeds and York Partnership Foundation NHS Trust, said: "He was complying with treatments that were being given to him at that point."
Senior Coroner Kevin McCloughlin asked her: "Did you foresee anything of the type of danger that might arise some days later?"
She replied: "No, not at all."
Mr Bosomworth had been acting aggressively and attacked the men on a ward at St James's after waking up following sedation.
He later told security staff he believed he had attacked burglars who had broken into his home.
Mr Bosomworth's stepdaughter Rita Martin previously told the inquest Mr Bosomworth had been diagnosed with schizophrenia in 1962 and had been stable for more than 50
years because he took anti-psychotic medication.
Mrs Martin said he was denied his anti-psychotic medication olanzapine in hospital despite her repeated requests for him to be given it.
The inquest heard staff at St James's Hospital were not aware Mr Bosomworth was taking olanzapine when he was admitted on January 27 2015.
The inquest was told Mr Bosomworth suffered a seizure in hospital on February 2 and on February 12 he was discharged to a care home without his stepdaughter's knowledge and
suffered a psychotic episode while there.
He was re-admitted to St James's Hospital on February 19 and assessed by mental health services on February 22.
The inquest heard he was not given olanzapine in hospital until February 24, when he was given a lower dose then he had previously taken.
Mr Bosomworth refused to take the medication the following day.
The attack happened on February 28 2015.
Dr Waddingham said Mr Bosomworth had a further "significant seizure" within 24-hours of restarting on olanzapine.
She said a decision was taken to give Mr Bosomoworth a lower dose of olanzapine because he was not deemed a risk to others but was at risk of further fitting episodes and falling while
on the medication.
Dr Waddingham said the plan was to introduce higher doses gradually and said it would have been "pretty wreckless" to introduce a higher dose at that time
After the attack, Mr Bosomworth was sectioned under the Mental Health Act.
Mr Bosomworth died of throat cancer in June 2015 after being diagnosed around two years previously.
The inquest was previously told Mr Lamb had stepped in to help Mr Godward when he was being attacked.
Mr Godward's daughter-in-law Lisa Dixon told the inquest she spoke to Mr Lamb in hospital before he died and commended his bravery.
Mr Godward died on March 3, 2015, from sepsis due to pneumonia with underlying Alzheimer's.
Mr Lamb died on March 5 from a chest infection due to a fracture of the right hip which ultimately occurred as a result of blunt force trauma.
The inquest continues.