I'll be honest and admit that I find the audio and evidence so gruesome and mean-spirited/abusive that I don't think there's anything Greenwood could have done to make me think he should have been back on the pitch. Even if he's genuinely remorseful, he can be remorseful without his footballing career.
I'm trying to think of any other stories where I felt that way about the athlete. I might be missing something but I think he's the only one where I thought 'ban him forever'. Actually, Tyreek Hill too.
The one that comes immediately to my mind is Michael Vick. What he did was horrible. It was also illegal and he went to jail. I’ve had 3 dogs of my own. My parents had two dogs. Brother and sister have both had dogs. My dogs are literally my children. That said, Vick paid the penalty society demanded of him. He also did a lot of work with the Humane Society, going into the kind of neighborhoods he came from and speaking out against dog fighting. As far as I could tell, he was sincere and the people he worked with speaking out against animal cruelty supported him. As an Eagles fan and dog lover it was uncomfortable at first but from all appearences it seemed that he really learned from his experience and changed because of it.
Greenwood is a different situation since he wasn’t convicted of anything, but even so I haven’t seen anything that suggests he’s made anywhere near the effort that Vick did to address the wrongs that everyone knows he did. Unless that were to change there’s no way I’d want him on my team.