No there is no backup or mirror image of software.

Think of it this way, as your P/C has a TCP/IP connection, you make a session with a host then plug the LAN cable.

Same here as the LS1edit interface as still plugged in so it was still taking to the PCM so the session was not completed as power to interface still had it active.
PCM I suspect then does not do a normal clearing of memory where averages like LTFTs are so they are not flushed out when starting engine has the old averages where normally they are erased after a flash is done.

Reason people have made the PCM into a brick is for whatever reason the session is broken during or right after flashing leaves he flash memory in a non complete state or the data no longer matches the CRC checksum the PCM no longer has a valid segment 1 software.