Ugh.... thats something I dread, wonder and severly PRAY DOESN'T HAPPEN!
I believe, alot of newer setups have a fail safe backup bios, incase this does happen. In the off case it does, and get a boot failure, the backup kicks in an starts up.
Honest though I'm not sure if ACER does this, but believeing it takes some of the scare away
The whole flash process was 30secs, so unlike old dos/.cmd line flashes, Its relitively no time at all.
I'd not be afraid.