AssertionError: Header not accepted on PS2268

[MikeRalphson]

I'm trying to run this on an ASUS Transformer T100TA which has an embedded 8Gb flash drive with the Windows recovery partition on it. I'm now running Ubuntu on this device and would like to rewrite this flash, but it appears to be read-only. Is there any software controllable read-only flag on this device?

mike:~$ sudo python3 ./drivecom.py get_info --path /dev/sg0
drivecom.py - Phison USB flasher and utilities
----------------------------------------------
Handling command 'get_info'...

Using USB drive:
	Path: /dev/sg0

Image version: 01.00.53
Chip type: 2268
Flash chip ID: 98DE989272D7
Mode: Firmware

I have tried reflashing the firmware (in firmware and boot modes) but I get the following error:

drivecom.py - Phison USB flasher and utilities
----------------------------------------------
Handling command 'flash_firmware'...

Using USB drive:
	Path: /dev/sg0

Opening firmware image Desktop/Stuff/Firmware PS2251-68/FW68FF01V10053M.BIN...
Firmware image read.
Transferring firmware...
Traceback (most recent call last):
  File "./drivecom.py", line 652, in <module>
    args.func(args)
  File "./drivecom.py", line 430, in drivecom_flash_firmware
    device.transfer_file_data(data, 0x01, 0x00)
  File "./drivecom.py", line 282, in transfer_file_data
    raise AssertionError("Header not accepted")
AssertionError: Header not accepted

The flashing actually appears to have worked, as it was originally showing version 01.00.10, but the drive itself still seems to be read-only (even if I use hdparm -r 0 and remount the drive).