I got the very similar issue, but my Surface EC firmware is okay.
I got the firmware from Windows Update (I click "Check updates" purposely), I didn't reboot immediately. But before the update got installed, my Surface got BSOD. Then it reboot.
During the reboot, it looks like the Surface is installing firmware like what ReSurfaceMan say, the system try to install multiple times until it failed.
Tried to install the MSI and nothing magical happened (DPINST.LOG say all drivers version looks good). Tried to click "Update Driver" in Device Manager, no luck.