NFL will look at the fumble-out-of-end-zone rule

Yeah he did....totally didn't see that.

But yeah, still don't agree with the changing of posession on a fumble out the side of the endzone. There's already a rule mechanism in place to deal with forward fumbles out of bounds...specifically on 3rd downs where forward fumbles out of bounds anywhere on the field are spotted at the spot where posession was lost. Expand that ruling to include fumbles out of the side of the endzone and viola - the source of frustration for fans all over is gone.
You're forgetting that the FIELD OF PLAY ends at the goaline and the END ZONE begins. How can a ball leave the FIELD of PLAY past the goaline unpossessed? There's a rule that governs what happens when an unpossessed ball passes through your END ZONE and that rule is titled a TOUCHBACK.