That I can understand. I found a link that can backup your explanation:
So pressing the power button while the power cord is removed will discharge the device in the event where it is not able to boot correctly. Learned something new today.
However, I still dont see how this technique would impact the devices memory or perform any other reset-like tasks. The OP here mentions that the printer is booting and displaying all sorts of error lights and flashing screens. If there were a power issue I wouldnt think the lights would be able to kick in and try to alert the user about the problem in the first place. Then again, maybe thats how this printer model is programmed to behave in a power surge situation?