It does look as if it was hit with the wrong end of the tool. I can believe one will break, otherwise not the way the one in the picture broke. Heck, that one looks coceivable like the round could of almost gone off.
I assure you it was used correctly. I rarely pull bullets with primers, I only use this to pull bullets fom primerless cases that I've set bullet depth/OAL with. Although I did pull 50 rounds once of 40 I thought might be too hot.
No response from RCBS yet btw.