> Alternatively, I could also say that the good Samaritan is actually acting in a way that is a detriment to his survival, and only happens because of a bug in his generic and psychological programming or an old beneficial feature that is no longer good for a new environment and will eventually be removed via natural selection.

Evolution does not "work" on behalf of individuals. It works on behalf of species. So if a member of a species is willing to sacrifice himself or take risks for the whole, that is an evolutionary feature not a bug.

If a species were truly focused on the individual, I imagine it would quickly die out, which, let's face it, seems like a threat to our species in our modern world when people choose not to have kids because they don't want the responsibilties involved.