Can circumcision go wrong?

Unlikely. If circumcision performed by an experienced & careful surgeon. Surgeon needs to be careful reading removal of correct amount of skin & meticulous regarding hemostasis (control of bleeding).
Life Is Uncertain. Can {fill in the blank} go wrong? Yes, of course. All procedures have a risk of complications. Just like there is a risk of having a car accident while driving a familiar route. Circumcision is a generally safe, easy procedure. But sometimes the unexpected can happen.