If you get paid hourly then perhaps. If it is irrefutable that its your fault/bug then you should feel obligated to fix for no extra charge/hours to them.
Currently illegal in most if not all US states. When an hourly employee does work, they must be paid for all of their time.
I certainly wouldn't want to see this change. Way too much room for abuse on the employer side. I think the current remedy is sufficient (if any employer thinks someone is screwing up too much, they can fire them).
The real spec is DoD 5220.22-M, available at http://www.dtic.mil/whs/directives/corres/html/522022m.htm.