I might be wrong but maybe him not willing to take less has something to do with how much he would make on his contract after this upcoming one. Maybe if he only takes the 55 mil, maybe that means his next contract couldnt be as much as it would if he would have got the 60. I think it has to do with your raise can only be so much. So it could mean more than 5 mil to him. And 5 mil is still a lot of money. Id take the money too.
Anyways, im not sure. I could have just made that up, but I thought I have heard something about that before.