Rollkur is also known as hyperflexion of the neck. Rollkur is basicly getting your horse to arch his neck through aggresive force. You are not pulling on your pony, infact you are convincing him to lengthen into the bit. Rest assured, Rollkur is acheived through force, and if you pony does arch his neck for you, its a good thing. It usually means his working his abdominal muscels and using his back, so he dosn't cave in behind the saddle.
Rollkur is banned by FEI, I think, seeing as though its a cruel method.
But trust me, no one is going to think you are peforming hyperflexion of the neck. As long as your horse has good movement, take your mind off of his neck and concentrate on other things, I can tell you are a good rider, seeing as though you are concerned for you pony. :]