I've got a Nexus 6P which used to run LineageOS and Twrp. When upgrading to the latest vendor image I accidentally downloaded and flashed a complete factory image. As a result the phone is stuck on the splash screen, and never boots into a working Android environment. Additionally, recovery gives me "No Command", but power+volume up gives me the recovery menu.
In the menu I've got various options. I can mount system just fine. I can't mount the sdcard, as the partition isn't found. If I select "Apply Update from ADB" it apparently goes into listen mode, but the phone isn't visible in the host computer (Xubuntu 18.04) through the
adb devices command.
lsusb also gives me nothing, and
udevadm trigger also changes nothing.
Is there anything else I can try in order to get data out, or is the only option left the factory reset option in recovery, alternatively a new phone?