There were two outs and Alcides Escobar was at first base when Pettitte threw a pitch into the dirt. Ball four, ruled home-plate umpire Mark Wegner.
"I thought it was 2-2," Cain said. "Then Esky kind of jogged to second and I went, 'Oh! That's a walk, I guess.'"
Pettitte said he wouldn't have buried the pitch if the count was 3-2.
"I know it's 2-2 and I'm bouncing a ball in front of home plate and everybody in the ballpark looks at me like I'm nuts," Pettitte said.
Statisticians charting pitches in the press box said that the confusion apparently came on the first pitch, which they initially counted as a called strike. (Later, after the walk, it was changed to a ball.) Cain agreed.
"It was a called strike. I thought it was down, but he called it a strike," Cain said. "Then I fouled off a few and took a few, and by that time, I didn't know what the count was."
Well, he didn't think it was a full count of 3-2 anyway.
"I thought it was 2-2," he added.
Clouding the matter was three pitches fouled off by Cain and several throws to first base by Pettitte.
Royals manager Ned Yost said he didn't see any problems with the pitch count, but Yankees manager Joe Girardi suspected a discrepancy.
"We thought in the dugout it was 2-2, and then I didn't see [catcher Chris Stewart] react," Girardi said. "A lot of times I go on the player, and [Pettitte] threw over about 10 times, so I thought, maybe I missed a ball. I'm not sure that I did."
The walk had no effect on the outcome. Alex Gordon followed by grounding into the third out.