Quote:
The lockup is just one of OS modes
Citation needed? I doubt microsoft explicitly implemented a mode in such a fashion - they have no need for that.
The thing is that many video cards have a dedicated cursor overlay, which means that in most cases you can get away from a mouse interrupt with two writes to some video registers. You probably want to do this straight from the interrupt as it has the least latency (set X and Y in the video driver), and you don't cause overhead by scheduling move-pointer events outside of interrupt context. If you compare that to a keyboard, it has little reason to do things directly from the keyboard handler, as the only thing it really needs to do is post the event, as the place that handles it typically is deep down in userspace.
So the only thing that happens during a "crash" is that there's no process responding to either keyboard or mouse events, and only the interrupt subsystem and it's shortcircuited logic work, giving you only the visual appearance of a moving cursor while in reality actual mouse
events are just as dead as any other.