As I understand it, the self-destruct feature was mainly due to:
(A) Luminary MCU on the main board self-corrupting flash memory (Note 1)
(B) STM SPEAR320 processor on the front panel failing for some reason, at least some get very hot to touch
(C) NAND FLASH on the front panel getting corrupted, sometimes recoverable by interaction over the serial port.
Keysight is the undisputed champion of FLASH corruption, perhaps not always their fault but certainly early firmware made a poor job of recovering from FLASH corruption. e.g. depending entirely on one copy of the NAND ONFI parameters, ignoring backup copies when primary failed
My hope (I say staring at my DMM) is that these problems have been fixed in newer dark colour meters. Certainly the main board and front panel processors have changed, we have to wait and see if there are reports of NAND corruption on these newer meters. So far, so good on my bench
Note 1: TI EOL document PCN 20140630000 for the LM3S Tempest/Inferno defective MCU product line gives estimated failure rate of 0.3%