Mistakes, I understand. Hiding behind "Mechanical Error" to avoid paying up on their guarantee is shameless and just plain wrong.
I agree, but I'm not sure this is a case of that. The infamous 1909 Lincoln slabbed as a matte proof? For that one, I would've been inclined to hold their feet to the fire. I think it does partly depend on whether someone paid up on the basis that they trusted the TPG's grade, even though it shouldn't. (Don't want "find mistakes and use them to cash in from the TPG" to turn into a full-time sport.)
One that just was sent to me; would be a HUGE "mechanical error" if that is how it is handled. Coin is certed as a 1796 w/o pole half cent and currently in a HIBid auction. I have notified the TPG and the auction house it is NOT a 1796, but a 1795 C-6... Image of coin: The reverse of a 1796 (either variety) is unique to that date; the reverse of this one does not match and is unique to 1795 C-6 (which is also a "no pole" variety)... Image is of this one's reverse to a known actual 1796: This could get interesting...
I'm not a half cent collector, but definitely noted the differences on the reverse as you mentioned. Oh boy, that is going to suck for any buyer relying on the NGC cert.
Yep; now described in the on-line cert as a "mechanical error"; even added my attribution correction...
Happened to me. I submitted a valuable quarter eagle with "D" mintmark and they slabbed it without the mintmark (implying it was Philly). I sent it back and they fixed it, but I had to call repeatedly to get them to expedite the change and not just put it back in line for ten days plus the shipping time. Making the phone calls paid off as they fixed and got it back to me within a week. Ironically when I first submitted it I first called to see which classification to use, the person I talked to told me the wrong one and they were quick enough to ask me for an additional $10. But when it came to correcting their error they were not going to prioritize fixing an error that made a difference of many thousands of dollars in the way it was listed and characterized in their database. Odd. I expected red carpet service on the error, but wouldn't have gotten it without calling and insisting on it. We can blame some of this on the pandemic I suppose.