Since it has a proper inscription, I would doubt that it's from the edge inscription step, unless... there was a stray piece of metal in the edge inscription step, but then I still have a hard time believing it would still receive a proper inscription.
I'm not a expert but that is not an error, looks like a smash not a clash. Looks like post mint damaged. Not every nic or dent on a coin is a error. Would you buy it!:hammer:
a coworker of mine found a prez dollar with the same kind of 'damage' or 'error'. i advised him to keep it if for no other reason then as a curiosity. However, i would be interested in any information someone might come across as to iff this is a minting error and what kind (how it might have happened0 and if the TPG's would grade em .... its a cool little find either way =)
If there was just one of them, I would probably say post-mint, but after seeing 4 or 5 with almost the exact same effect, I would say it was something in the edge printing process, definately mint caused.