Seems plausible. HDToolbox is trying to scan all the drives and devices, I bet it doesn't know WTH to do when it hits the Google Drive device. 
Actually it is not plausible. All it needs to scan are exec.library devices, not dos.library devices. The Google handler does not have an exec.library .device, so it does not need to touch it.
Even if it scans the DOS list for whatever reason, the Google handler can clearly be identified as a drive without a .device.