He was measuring from the bumper cover. The problem is that is a body on frame vehicle, a small difference between body and frame or on unibody cars the engine cradle and body can be multiplied many times when measuring like this.
It also is not an indication of damage from an accident, it could be something as simple as the engine cradle being lowered to replace an oil pan, engine mount, steering rack, sway bar, etc and bolted back up without aligning the cradle.
On full frame vehicles it is not uncommon for the body to be lifted to gain access for some repairs that may result in a very slight insignificant shift.