Sounds like both of you are having issues with a bad wheel speed sensor. The codes are still stored, even though the light is off. It keeps a history for something like 60 key cycles. So get it scanned and get it taken care of.
The problem with just letting it go is that it will make your ABS act all weird. Sure doesn't seem like too much of a problem. But you never know what it is going to do under hard braking if you are having issues. Could lock one wheel up, and not the other, and send you into a spin. Not good when you just need to stop.