There are a couple of reasons why he got the loss. A. You have to complete 5 innings to even be eligible for the win. Kuroda only pitched 1 1/3 innings, he didn't even make it out of the second inning. B. It doesn't matter how many of the runs he gave up, as long as he was the pitcher of record at the time the opposing team had the lead (and then never gave it up), he is the losing pitcher.