How bad is shorting PPBUS_5VS2_VIN(12.3V) into PP5V_S2(5.1V)?

Title:

How bad is shorting PPBUS_5VS2_VIN(12.3V) into PP5V_S2(5.1V)? M1 MacBook Air now stuck inside a restore boot loop!

These videos showing how the MacBook Air M1 looks right now:

1. How the machine is stuck inside a boot loop now 
2. How the machine failed the revive and restore operation by Apple Configurator

For more background please refer to my previous post. Now I have done more measurements and now I post it here.

What is the disaster?

My MacBook Air M1 was stuck in an exclamation mark restore loop. It can’t enter recovery mode, It can't be revived or restored by Apple Configurator. The power button can’t even power off completely. I believe this was caused by me accidentally shortening PP5V_S2 (5.1V) into PPBUS_5VS2_VIN (12.3V) with a multimeter probe. It produced a spark and a click sound, then the motherboard rebooted and then bricked.

I measured the point voltage of these two points, PP5V_S2 is 5.1V, and PPBUS_5VS2_VIN is 12.3V. According to schematics, PP5V_S2 should be at around 5V, but was once shorted into 12.3V. I especially want to know what component has the highest probability to get damaged by this disaster? What chips should I focus on checking?

Since the MacBook can power on, and the USBC voltage and other major voltage rails all look normal. I have assumed power management chips are okay.

I went through the rail trace, this can be one of the possible trace routes of the 12.3V pulse going all the way to the NAND chip and kill it:

1. PP5V_S2 (UF400 > U5700)
2. P3V8AON_DRVL1 (U5700 > R5805)
3. P3V8AON_DRVL1_R (R5805 > Q5800)
4. P3V8AON_VSW1 (Q5800 > L5800)
5. PP3V8AON_PH1 (L5800 > R5800)
6. PP3V8_AON_VDDMAIN (R5800 > U7700)
7. PP2V5_AWAKE_NAND (U7700 > UN000)

Questions:

1. Do you think the NAND can still get damaged by this 12.3V pulse after so many components (two power management chips and five resistors sitting between)?
2. By looking at the current symptoms, does it look like a NAND issue at all?
3. Are there any other chips that can also prevent the NAND read-write activities? When the CPU writes to the NAND in DFU, everything looks normal, not a single error message prompted.

Please help, any comment is welcome.