Neil McCormick plunged sixty feet and landed on rubble after he was spotted walking in circles and mumbling ‘guys, don’t do this to me’, the court heard.
Mr McCormick, who had used cocaine regularly since studying at Oxford University, moved to Hong Kong last September with his wife Diana and baby son.
In June, the 36-year-old head of Asia Equity derivatives at UBS returned home for a wedding. The day after the ceremony, friends held a barbeque in his honour.
But after treating himself to steak and a beer, the banker was seen by Connor Kelly, the owner of the house in Holland Park, west London, snorting a line of cocaine from a plate in the kitchen.
Westminster Coroners’ Court heard the banker went to lie down at some point in the afternoon, before getting up a few hours later, at around 7.30pm.
He returned to the kitchen where he started muttering to himself and walking aimlessly.
He then went out on to the patio on the forth floor, vaulted across some pot plants and on to scaffolding, before he jumped to his death.
Connor Kelly told the court: ‘When he arrived he seemed perfectly normal. He was chirpy.
‘When he got up from his nap he came in, circling around the intermediate area between the sitting area and kitchen, circling around there mumbling to himself.
‘I thought I heard him say the words “guys, don’t do this to me”. It was barely audible. It was certainly odd.
‘I saw him walk out across my patio and basically vault the window boxes. Then there is a concrete balustrade, and he basically vaulted from that onto where I was having some exterior decoration done.
‘I saw him vault between the window boxes and the balustrade, then there was a scramble. That’s the image I will probably have solidly with me forever. He steadied himself, and that was it.’
Mr Kelly rushed to his back garden along with his doctor brother Cieran to try and help their friend.
‘He was actually a decent way out from where he fell. It was a jump, not a step.’
Another friend at the party, who Mr McCormick had known as a chemistry undergraduate, said the barbeque was ‘a big celebration for Neil coming back’ and had been planned for a couple of months.
Recounting the evening, Stefan Kazubowski said: ‘He seemed really good. There was a lot of banter back and forth. There was a lot of gabbing with him. We were having a laugh, as always we were in hysterics.’
But he said Mr McCormick changed after his sleep.
‘He seemed agitated. He walked around the room and then out onto the balcony, and because I saw he was agitated I followed him just to find out what was wrong.
‘I was concerned because he seemed upset. I know that Neil could get a little bit paranoid at times and he seemed a little bit paranoid.
‘If he had ever taken drugs in the past it didn’t always react well with him. I tried to speak to him in a normal level voice.
‘He didn’t respond and carried on walking to the end of the patio and climbed onto the boxes that hold the shrubs. In one large step he then went onto the scaffolding, and at that point I called quite loudly.
‘I called again very loudly as he took his second foot onto the scaffolding.
‘Just for the briefest moment he steadied himself before he stepped off.’
Coroner’s officer Kola Omadoye said: ‘Mr McCormick had a long history of recreational cocaine use, since his time at university.’
The court heard that Mr McCormick had no history of mental health trouble and that his marriage was an extremely happy one.
Deputy Coroner Shirley Radcliffe said: ‘I don’t believe that the intention was to kill himself. I think he was obviously, from what we have heard here, in an agitated state.
‘We heard he had previously acted in a bizarre way when he had taken cocaine. I think he was under the influence of cocaine and not fully aware of what he was doing.
‘The toxicology reports showed his blood contained metabolites of cocaine, 0.92 milligrammes per litre, which is above the normal recreational level. Recreational use is normally around the level of 0.6 mg per litre.
‘My conclusion to this death is that this is a result of misadventure as a result of the cocaine he had used earlier in the day.’ – Dailymail