Stopping boar steal

I played a lot against the barbarian AI lately and became curious regarding the best method to stop a boar steal attempt. Barbarian tries to lame every other game, so it's great practice in that regard. Blocking the boar doesn't seem to do much, because the AI will just slow down its own scout accordingly. Is it generally best to block the enemy scout to let the boar catch up or just smack the scout until it dies?