First, my case was out of TSC processing time so that I had my lawyer send out service request a couple of time. My lawyer thinks that's how RFE was triggered. I guess the office was too busy to look up my case and sent out email notice to delay the process.But later on, he/she found my backgound is OK and my lawyer is strong. So, he won't bother and just let me go.I have no idea if the officer withdraw the RFE.
Search in this forum with key word "RFE", someone posted a similar story before.