I spent a couple years thinking about this risk every time I rebooted and got the white screen prompting me to press space to restore ChromeOS. In reality, at

I spent a couple years thinking about this risk every time I rebooted and got the white screen prompting me to press space to restore ChromeOS. In reality, at least for the Dell Lulu platform mentioned above, what will actually happen is it will probe for recovery media first. In the event that it doesn't find any, it will leave the underlying system untouched and just complain at you about it (and tell you to go visit a URL on another computer so you can create a USB/microSD recovery disk).