It isn't errant, there are just two processors handling different tasks.
This is basically a BeagleBone Black with an integrated Arduino (for low-level compatibility with the Arduino shield ecosystem) that the more full-featured (but less real-time friendly) Linux-running part of the board can drive.
The Atmel ATmega32u4 (the Arduino bit) is 16MHz, the more full-featured Linux/ARM part runs on a 1GHz Sitara AM3359AZCZ100 (ARM Cortex-A8) just like the BeagleBone Black.
This is basically a BeagleBone Black with an integrated Arduino (for low-level compatibility with the Arduino shield ecosystem) that the more full-featured (but less real-time friendly) Linux-running part of the board can drive.
The Atmel ATmega32u4 (the Arduino bit) is 16MHz, the more full-featured Linux/ARM part runs on a 1GHz Sitara AM3359AZCZ100 (ARM Cortex-A8) just like the BeagleBone Black.