The question isn't about the MHZ speed of a computer or the theoretical reaction time but the lack of reaction by the computer in the actual real world. It doesn't matter if this is a sensor failure, a software bug, or a slow reaction by a computer. The result is the same. A person died.

From the article:

*"... the lack of braking or swerving whatsoever is alarming and suggests that the system never anticipated the collision.”