"Mr Marshall, by any token, was desperately unlucky and so by the same token, is we say, this accused,'' Mr Percy said in his closing address.
Crown prosecutor Amanda Forrester said there was no explanation for Schmidt's unjustified attack on Mr Marshall other than a fit of rage.
She likened the incident to picking up a gun, pointing it at somebody and firing, without checking whether it was loaded or in working order, then realising the safety catch is not on.
"He did not just push him towards the window, he pushed him at it, into it and through it,'' Ms Forrester said.
"He was like a coil, ready to spring and he sprung at Mr Marshall.''
Mr Percy said there was no motive for Schmidt to kill.
"Obviously it has not been the end of the night that he wanted, but in terms of having a murderous frame of mind toward any hapless individual who crosses his path, that I suggest to you is untenable,'' he said.
Schmidt gave evidence on Monday that he had been drinking alcohol since 10.30am, taken two ecstasy tablets and smoked several marijuana joints on the day of Mr Marshall's death.
At some point in the night, Schmidt and a friend had a fight about a woman.
To resolve the situation he decided to ask the woman to leave and then he noticed her talking to Mr Marshall.
Schmidt told the court he told Mr Marshall to "f*** off''. Marshall replied with something Schmidt couldn't recall before the New Zealand man was pushed to his death.
Justice Ralph Simmonds is expected to direct the jury today.
