Evidence to the tribunal said matters "came to a head" about four months later, when the patient, known as Ms V, told her key worker "Collin wants to f*** me".
An investigation led by Suzanne Kerruish, Service Manager of Adult Community Mental Health Services, revealed Kora's phone records.
Ms Kerruish also received a letter from a social worker describing how one of her clients, known as Ms N, received a phone call from Kora late one evening.
Kora allegedly asked the patient if he could come round and watch DVDs with her. She declined, saying it was late and she was tired.
When Ms Kerruish met with Kora over the allegations, his initial response was that "both clients were paranoid schizophrenics and they must have misinterpreted what had occurred".
However, he later opted to resign from the health board after being threatened with dismissal.
The tribunal's judgment said it took into account Kora's repeat offending and the extreme vulnerability of the patients he had inappropriately contacted.
It said his suspension was effectively for 18 months, as he had been originally suspended when proceedings were launched against him in February last year.
"The tribunal censures Mr Kora. This is not a formality. It is at mark of the Tribunal's significant dissatisfaction with behaviour of this kind and the inappropriateness of such misconduct."
Kora was only allowed to return to work on the condition he undertake an ethics course within a year of restarting employment.
He was to work under direct supervision for at least 18 months, the tribunal ordered.
- HERALD ONLINE