There's not enough public information about it - but taking this talking point at face value, Microsoft did sign their kernel driver in order for it to be able to do this kind of damage. It's not publicly documented what all validation they do as part of the certification and signing process:
The damage may have been done in a dependency which was not signed by Microsoft. Who knows? Hopefully we'll find out.
In general, a fair amount of the bad behavior of windows devices since Vista has been really about poorly written drivers misbehaving, so there appears to be value in that talking point. All the Vista crashes after release (according to some sources, 30% of all Vista crashes after release were due to NVidia drivers), notably, and more recently if you've ever tried to put your Windows laptop to sleep, and discovered when you take it out of your bag that it had promptly woken back up and cooked itself into having a dead battery. (Drivers not properly supporting sleep mode) WHQL has some things to answer for for sure.
https://learn.microsoft.com/en-us/windows-hardware/drivers/i...
The damage may have been done in a dependency which was not signed by Microsoft. Who knows? Hopefully we'll find out.
In general, a fair amount of the bad behavior of windows devices since Vista has been really about poorly written drivers misbehaving, so there appears to be value in that talking point. All the Vista crashes after release (according to some sources, 30% of all Vista crashes after release were due to NVidia drivers), notably, and more recently if you've ever tried to put your Windows laptop to sleep, and discovered when you take it out of your bag that it had promptly woken back up and cooked itself into having a dead battery. (Drivers not properly supporting sleep mode) WHQL has some things to answer for for sure.