Those who have already said to question the bowler directly are right-on. If your teammate doesn't feel this way at all, but is only the victim of hearsay, kicking him/her off the team is unfair.
If your teammate affirms the hearsay, and that approach is not in keeping with the team's goals, the teammate should be invited to leave if his/her attitude doesn't change. So, if your team's goals are and have been to do your best and try to win first place, any intentional wrecking of scores, especially to benefit another team regardless of the reason, is unfair to the team.
--------------------
Kill the back row (or maybe this should read "make your spares, dummy")