Kinda funny....That sure dosent mean its grounded? If you have plastic J boxes, and no grounds hooked up to it? Im sure he didnt take the receptacle out and check. Maybe standard procedure now?
We will never know because you have no clue if the outlet is grounded....Some people did this years ago for static, and hums,(audio) but if not grounded its doing nothing.Is that ground according to code?
Actually the outlet is grounded because the white neutral wire is grounded at the breaker panel is it not?