I don`t buy that theory at all.No body places a scope in the rings in exactly the same place as another person does.So if you take a rifle that is pre set up and sighted in.No two people are likely to put their head in the same place as another person does.Everyone that shoots the rifle will likely have a different point of impact and it has nothing to do with knowing how to shoot with a scope.It is the difference in human physical proportions.That is why women with long slender necks shoot a stock with a high roll over comb better than a man with a shorter neck and broad shoulders that is more comfortable with a straight classic style stock.That is why tactical stocks are fully adjustable for LOP,comb height,grip angle.Well the first thing that comes to mind is that the app info is probably wrong at the ranges that you are shooting at. While apps are good for getting you in the ball park, they do not take into account all of the different variations that one encounters out in the field or on the range. The fact that the errors are repeatable also lend me to believe that it is an app problem. Moving on, other factors that might be causing the issue is simply an issue with the parallax adjustment on the scope, if it has one. If not that means that the parallax is factory set for 100 yards which is not ideal for shooting at any range over or under 100 yards. Without adjustable parallax compensation the slightest movement of your eye from exact center of the aperture means that the bullet will follow your head movement. The longer the range the smaller the movement required to end up in an error. Moving on, there was a comment that one persons scope would shoot right but his son using the same rifle would have the same rifle hitting left. This again relates to parallax and the placement of the eye outside of the exact center of the aperture. If a person knows how to accurately shoot a scope and zeros the rifle, any other person who knows how to shoot a scope should be able to pick up that rifle and shoot and hit exactly the same spot it was sighted in for by the other person. The only argument here is who knows how to really shoot a scoped rifle and zero's it and who else knows how to shoot a rifle zeroed by the other individual. The bullets will hit in the exact same spot for either them or anyone else who really knows how to shoot a scoped rifle.
As to the question of why the rifle shoots to the left,the best idea is to have some one video tape a whole sequence of your shooting.You may not think you are shifting positions as you shoot,but the tape will tell you.The most failure I have seen with folks pulling one way or the other is bad follow through.Huntz