I'll bet he didn't.
I have used WLP's for 40 years. I used them in multiple .45's, and three different .44Mags. I probably averaged about 1000/yr in that time.
Never had a single dud, or failure to fire. I have also used CCI's and Federal's from time to time, and never had any trouble with those either.
Somehow the mystery man stiffed you with a poorly stored batch.