During 85 minutes of evidence on Tuesday night at the NRL's Moore Park headquarters, Crossland said the incident had taken the focus off grand final week.
"Apologies to everyone involved in the game," he said. "I hope after tonight we can get back to the football.
"If I could change the circumstances in any way, I would."
The suspension over the tackle in Newcastle's win over the Panthers in last Sunday's preliminary final, means Crossland will not only miss this Sunday's grand final against the Sydney Roosters but also the majority of the World Cup for New Zealand.
Crossland, who has played six Tests for New Zealand, will now miss all three pool games for the Kiwis against Australia, the Cook Islands and Fiji. New Zealand would have to make the semi-finals for him to feature.
The 26-year-old also revealed he had contacted Cleary and his father, Penrith coach Ivan Cleary, to apologise.
"It was a tough phone call and I just wanted to reach out and apologise," Crossland told Judiciary chair Geoffrey Bellew and panel members Ryan James and Paul Simpkins.
"It's been the worst couple of days of my life.
"He's my favourite player by a mile and the only reason he's in hospital is because of me."
Knights counsel James McLeod had asked for a penalty of no more than three matches given Crossland had shown deep remorse and had pleaded guilty.
NRL counsel Patrick Knowles SC said that while there were mitigating circumstances, a penalty of four matches was appropriate.
Cleary's injury was one of the worst suffered on an NRL field this season.
He underwent emergency surgery in Sydney's Royal North Shore Hospital on Sunday night.
Cleary is also Australia's incumbent halfback but will also miss the four-week World Cup, which starts on October 15.
Crossland's 1077 tackles this year are the most of any player in the NRL, with the incident on Cleary only the second time he had been charged in 2026.
The Newcastle hooker cut a dejected figure before being sent off and while in the change rooms on Saturday night.
Tuesday night's decision came after Cleary called out those peppering the embattled Knight with social-media abuse and threats.
"Please don't be one of those people writing comments like this to Phoenix," Cleary posted alongside a graphic of some of the abuse Crossland had received.
"It was a complete accident and he doesn't deserve the unwarranted hate. He reached out to apologise and I have nothing but respect for him.
"He's a competitor and our game is made up of split-second moments that sometimes lead to unfortunate circumstances.
"Comments like this are so unfair. Spread love, not hate."
