Probably drew parallel lines instead of with slight divergence so lane is 1" wider at circle than at pitcher's plate. Excerpt from NCAA rules:The during the AU AL game saturday, the announcers talked about how the pitching lane was 1 inch narrow and the grounds crew had to make it wider.
2.21 Pitcher’s Lane
The pitcher’s lane is the area to which the pitcher is restricted when delivering the pitch. It shall be 8 feet in length extending along the outer edges of the pitcher’s plate toward the inside edges of the inside front corners of the batter’s boxes. It is 24 inches wide at the pitcher’s plate and 25 inches wide where it intersects the pitcher’s circle.