Unfortunately, no, it doesn't really say how ZFS behaves when an error is encountered.

This is super-disturbing and a dealbreaker, if it's still true:

> The scrub operation will consume any and all I/O resources on the system (there are supposed to be throttles in place, but I’ve yet to see them work effectively), so you definitely want to run it when you’re system isn’t busy servicing your customers.

I browsed a little of the oracle.com ZFS documentation but couldn't find much in the way of what triggers it to decide that a device is "faulted" other than being totally unreachable.