Suppose Santana gave up one run on a homer to the first batter, came out because of injury, and the Angels lost 2-1, but never tied the game up?

Or 3-1 or 4-1?

Where do you draw the line as to whether or not to give the loss to a SP who leaves after one or two batters because of injury?

What MLB wants to avoid, I think - which is not necessarily a good thing - is subjectivity in awarding wins and losses.

I hate it when a SP leaves a game tied 1-1 after 8 innings, his reliever gives up a run in the top of 9th, and his team scores two in the bottom of the 9th to win the game, and the reliever gets the win.

If you want to look it up, I know there are circumstances in which the official scorer can award a win to a pitcher other than the pitcher that the "formula" would call for if that pitcher pitches ineffectively, though.

But I don't believe there are any exceptions for awarding a loss.