Looks like it blacklisted in #3177 device_recovery step after trying to reset_usb

E   12.390s Main  Unable to reset USB for 0a38ca3e.
Traceback (most recent call last):
  File "/b/rr/tmp5cxGPF/w/src/third_party/catapult/devil/devil/android/tools/device_recovery.py", line 149, in RecoverDevices
    reset_usb.reset_android_usb(serial)
  File "/b/rr/tmp5cxGPF/w/src/third_party/catapult/devil/devil/utils/reset_usb.py", line 50, in reset_android_usb
    'Unable to determine bus or device for device %s' % serial)
DeviceUnreachableError: Unable to determine bus or device for device 0a38ca3e
I   12.390s Main  Adding 0a38ca3e to blacklist /b/rr/tmp5cxGPF/w/src/out/bad_devices.json for reason: offline

Also, in the same step, it looks like it was at least initially present during lsusb:

I    9.006s Main  [host]> lsusb -v -s 002:011
D    9.104s Main  STDOUT+STDERR: 
Bus 002 Device 011: ID 18d1:d002 Google Inc. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x18d1 Google Inc.
  idProduct          0xd002 
  bcdDevice            2.28
  iManufacturer           1 asus
  iProduct                2 Nexus 7
  iSerial                 3 0a38ca3e

Lastly, it recovered itself in the subsequent build: #3178 https://uberchromegw.corp.google.com/i/chromium.perf/builders/Android%20Nexus7v2%20Perf%20%283%29/builds/3178

Looks like this has stabilized.