Whose fault is this?

There was no Gus buff and the map was Brawl Ball. When defending, Stu should have just pushed the ball forward, but they insisted on passing it to me (Gus) who was behind. Fortunately, Shade and I managed to push forward somehow, but Stu retreated with low health, and instead of healing, they just chipped away from afar with their attack range not even reaching, then died. So we had to defend again, but Stu, claiming they had low health, hid in a corner again and couldn't defend. That's how we lost the ball. Then Stu started blaming others.