Recently installed an app on iPhone to try to keep track of those not knowing I am keeping track. This persons name will be "phone".
Same day about four hours later phone was located stationary for 11 minutes, 9 miles from where phones office is and where phone states was all day.
Before my mentioning I decided to drive to this location for clearer insight. I used my iphone at the same location and its gps was accurate to within 3 feet.

Will an iphone gps give a location in that is 9 miles in error? Is it even possible or will it just relay a default message? I am new to gps and I am sure I am no longer giving phone a reasonable amount of doubt. Please provide insight to gps and how they could be this far off with facts only. Not looking for more counseling