Engine Failure because of wiring?

This is about an air-cooled 6-cylinder boxer.
The car has very strange engine damage. All pistons on the left bank (1-2-3) are broken. Nothing at all can be seen on the right bank.
i noticed the following on the wiring harness:

  • the outputs of the injectors are only wired with 22AWG
  • only one powerground was connected to the control unit!
  • only one 16AWG cable goes from the 12 Volts supply relay to all injectors and ignition coils (6 injectors and 2 ignition coils)
    Unfortunately there are no data logs for the period in which the damage occurred…
    Do you think there is a connection here? By the way, the control unit is not damaged.
    I just don’t understand why only one bank has damage while the other bank looks completely fine… if the engine had knocked, you would be able to see it on all cylinders, right?

Thank you very much for your help!

Possibble, but also it might be fuel pressure starvation on one side(probably further from the fuel inlet).