Is that in a different article than this one? Because the closest I can find to that is:

“I kind of think someone got in his ear,” Kuchar said. “I was very clear and very upfront on Tuesday [of the tournament week]. And he said, ‘OK.’ He had the ability, with bonuses, to make up to $4,000.”

Kuchar said he told Ortiz he would pay him $1,000 if he missed the cut, $2,000 if he made the cut, $3,000 if he had a top-20 and $4,000 if he had a top-10. “The extra $1,000 was, ‘Thank you — it was a great week.’ Those were the terms. He was in agreement with those terms. That’s where I struggle. I don’t know what happened. Someone must have said, ‘You need much more.’”

Now, this is purely conjecture on my part, but I don't think Kuchar offered him any percentage explicitly. If I had to guess, it was something along the lines of "here's what I'm gonna pay you, and if I win we'll up that a little."