I wasn't watching (have the Yankees game on), but I'd assume that Olsen probably intended to pitch around Graffanino, but missed with a pitch and Graf made him pay.
You don't want to straight up intentionally walk him...you'd rather he chase a bad pitch and half Suppan lead off the next inning.
Either way, Olsen had to have fucked that up. Sucks. Hopefully the Fish can rally here, it'd be a nice dog to cash.