On February 25, the defendant was walking through town when he bumped into a woman who had been locked out of her Queen St apartment building.
They sparked up a conversation and eventually "tail-gated" someone into the complex who had a key.
The victim tried to get into her bedroom through a window but was eventually let in by a flatmate.
Meanwhile, Wedervoort walked off, having taken note of where she lived.
His father was adamant the attack was not premeditated.
His son told him he was looking for a friend's place but had the wrong building.
Later he returned to the open window and climbed into the woman's bedroom, waiting there for her.
When she came in Wedervoort made a sexual advance but was rebuffed.
Rather than leave though, he held the woman down, put his hand over her mouth and violated her.
Eventually she alerted her flatmate and the 22-year-old fled.
But the following day, police released a CCTV photo of him from inside the corridors of the apartment, which saw him arrested shortly afterwards.
Mr Wedervoort said it was not a surprise to hear drugs and booze had been a factor in the incident.
Going out partying and getting home in the early hours of the morning before going to work the next day was unthinkable for the Dutch-born man but not so for his son.
"For most of the kids nowadays, that's how they live. They work hard and they play hard," he said.
Regardless, Mr Wedervoort told the Herald there was no justification for what happened.
All that was left for he and his wife was to support their son, he said.
"That's all I can do as a parent. You can't say you like what he did but on the other hand there's nothing you could've done about it," he said.