I have seen interference from one part of set top box to cause noise on flash input lines and sometimes issue a command to clear flash on the device.

Months of debugging, dozen people involved, tens of thousands of devices bricked, tens of millions lost.

All due to a single line of code that configured flash to not require special magic before each command. This feature made to improve resistance to interference also hindered performance. Somebody thought it a good idea to disable to get some points for improved performance.