It is not impossible that the comnpany did in fact do that, if it was a production defect, grinding the logo off would be a reasonable way to ensure the scrap yard didn't try to sell it as a good tool , it could also be a warranty return that the company didn't want returned again.
It could also have been defaced by an owner company so employees would have less incentive to steal it and sell it...
or it could just have gotten stuck in a grinding machine on a bad day...