That's not unusual at all and, in fact, is quite common. It's all about relative head position on the stock in relation to the scope and reticle, and how you pull the trigger. Since no two people are built exactly alike or pull the rigger in exactly the same way, the rifle will typically shoot differently for each individual. If you are relatively tall and the PH you borrowed the rifle from was short, the difference is that much more pronounced.

This is quite an interesting thread!! I wonder if any of the folks from CZ USA have peeked in?