[9rx]

Racism is a social bias that isn't "hardwired". It does not trigger the "fight or flight" response like was described in the earlier tale. Anxiety, of course, describes a "fight or flight" system that is malfunctioning. It is the most likely explanation because that is what was originally described. Mind you, the story could have been misrepresented. We do have to put our faith into what was written.

Another comment suggested that Altman was once beat up by a black man. If true, it is possible Sam has developed a conditioned response that associates black men with danger and his reaction stemmed from that. However, that isn't the same thing as racism and to try and categorize it as such would be quite disingenuous.