A jury returned a narrative verdict on Wednesday after a six-day inquest into the death of 29-year-old Moncef Kaddouri.
Mr Kaddouri, who had a troubled psychiatric history, with frequent episodes of depression and thoughts of self-harm and suicide, had been detained under the Mental Health Act 1983 at the Becklin Centre in Leeds due to concerns about his welfare.
On October 19 2017 he was allowed to take some fresh air, accompanied by two members of staff but managed to escape.
Police were called and he was found in his own flat on the 13th floor of an apartment block.
Efforts to force entry failed and a locksmith was called. But as an officer entered the living room in the flat, Mr Kaddouri, who appeared to be holding on to a window ledge, fell.
The jury at Wakefield Coroner's Court found Mr Kaddouri’s intention “was not to die”.
They also said the centre did not adequately assess the risk that evening and the patient should not have been granted ground leave on the evening of October 19.
They concluded: “On the balance of probabilities, an act or omission by the Becklin Centre contributed, more than minimally, to Moncef’s death.”
Sunny Sandhu, a solicitor at Switalskis, said Mr Kaddouri’s mother hoped lessons would be learned from his death.
Mr Sandhu said: "Mr Kaddouri's mother believes that the Becklin Centre was not a safe environment for her son and has expressed significant concerns for current and future patients.
"She sincerely hopes that lessons will be learned from her son's death that will result in the creation of safe environments for patients detained under the Mental Health Act."
Director of nursing at Leeds and York Partnership Foundation NHS Trust Cathy Woffendin said they had made improvements following the tragedy.
She added: “This was a tragic incident and we would like to reiterate our sincere apologies and condolences to the family of Mr Kaddouri.
"We understand that this has been an extremely difficult and upsetting time for everyone involved.
"We conducted a thorough investigation after this incident took place in 2017 and we’ve improved our practice since then."