Slim, it's just a result of the ejection process. Depending on the design of the gun some will do it and other designs not. It occurs when the case hits either the barrel hood or part of the ejection port... again, depending on the design.
Your sizing die and flare will will bring it back to loadable condition. Don't lose sleep over it.
Life is a little bit tragic but mostly magic... Learn to deal with the tragic and CHERISH THE MAGIC
A PACIFIST is someone who won't raise their hands to defend themselves...
A COWARD is someone who won't raise their hands to defend someone else.