Some of these comments to HA are unfair: he is not saying that no one else is an altruist, but only that he isn't. So he also doesn't care about the pain inflicted on the toddler's parents, for example.

Still, I'm afraid he hasn't considered all the consequences: when the toddlers burn up in the orphanage, the economic damage (in this case, the loss of the toddler's future contribution to society), may end up lowering HA's persistence odds. Certainly we have no reason to believe that it will increase them. So HA should really care about rescuing the toddlers.