I can't think of one, so this is only a halfhearted attempt (not the GP here)... maybe he's focusing on the mismatched firmware vs. OS version and how that is more closely analogous to a bad BIOS flash?

I'm undermining my own counterargument... On a PC, a bad BIOS flash is recoverable. Some have two BIOSes - like on video cards. Some have a recovery mode via a USB stick. And attaching a programmer to the SPI flash is also a viable recovery method...

Maybe he doesn't think any of the mac firmware environment is really that different from a general purpose computer?

Ok, I don't know what the counterarguments are. ¯\_(ツ)_/¯