Sheena and Macau could tell that Hubert was definitely repenting of his past actions. He was even slight bowing in front of them when he asked for the second chance.
"Well, you can try," Grey answered before Sheena and Macau could say anything. "Red is an absurdly kind person so if you kneel in front of him, maybe he will allow it. And as a cherry on top, maybe by offering your life to him, you might give your teammates a chance to join the Block. I'm just saying."
Because of the past guilt and his conscience screaming in his brain. Hubert was not in the right state of mind at the moment. That's why when Grey gave him some suggestions, he just nodded and acquiesced to it, thinking that that's the only way Red would accept them back in his Block.