In baseball, the total and run lines are action if the game goes 9 innings, 8.5 if the home team is ahead at that time, even if the game is called while tied after that.
If the game doesn't go 9 (or 8.5 if the home team is leading) innings, totals and run lines don't count. It works both for and against unders and overs. You could have under 8, the total would be 2-1 after 8 innings, the game is rained out and ends at that point. No action. You got screwed. Too bad. You could have under 8 and the score was 15-12 after 8 innings, and the game got rained out. No action. You got lucky. Same way for overs. You can get screwed or you can get lucky. It doesn't just work one way.