What Would Cause This?

Inside of pliers applied to coin (the wire-cutter part).

Looks more like side cuts were used on the coins. Side cuts are used to cut wire to length. On pliers they can be used used that way, but the cut would not a tapered but like I see on the OP's coin. Note how the cut tapers on these coins? With the pliers it would be square ended blunt.

If I could find my old pair of Linesman "snips" I used years ago as a telephone installer, wer officially called "Electrician's Scissors", I'll make a short vid of what they can do to a cent. I used to give everybody my " Half Cents" worth of advice. When those suckers were new, they literally would cut through like "butter". Used them to cut through 25 pair phone cable with one whack, lot easier than a side-cutters which took multiple attempts or "Nines" (9" heavy cutter/pliers). Really was a "show-off" for the munchkins!