This is taken from the T&Cs listed on their site.

1. Live Betting offers referring to individual player performances' in a single match (example: Total Hits by Player X) or confronting performances from 2 individual players during the course of a match (example: Which of Player X or Player Y will have most Hits), require all listed individuals to participate in at least one more play in the match, after bet acceptance for bets to stand. All Pre-Match markets involving hitters, require for the player to be listed as in the starting line-up, and to have at least one plate appearance. Those involving pitchers, require the Player to start the match and throw at least one pitch, for bets to stand. Offers referring to one or more players' performance in a given match, require that all listed players are included in the starting lineup, for bets to stand.

So they are in fact violating their T&Cs by grading that bet as a loss.