While the presence of a few piece of plastic by themselves pose no immediate harm to your reef, I would still be concerned that those pieces even got in there in the first place. If a few pieces of plastic can find its way into a bucket of salt from a manufacturer, what other unseen foreign contaminants could get in there? What if that plastic bag had previously held something nasty?
And ya, I don't see that Wes has done anything wrong by posting his findings. It isn't like he was bashing on a vendor. He found stuff in his bucket of salt that was unusual and he shared it with the community. Don't we encourage this sort of thing????
Also, this thread has demonstrated the integrity of the vendor that supplied the salt. Kudos to Snappy and the wholesaler for making it right.