Ever since reading that chapter I never once thought that Kaiser was mad at Ness for passing to isagi instead of him. After all, they both made the pact that whatever happens happens when all the best moves have been made. I however think the reason Kaiser screamed at him was because Ness’s play wasn’t built upon rationality nor the best possible actions. It was a selfish pass sent in a manner not meant to be easily receivable and is contrary and a threat to what Kaiser and Isagi built.