Names changed to protect the marginally innocent.
A well-known dealer sold a raw 1952 topps card to a collector putting together a high grade set which he eventually finished...and he spent a lot of $ with well-known dealer.
Collector, who is not well known, sends card to unnamed grading company.
Unnamed grading company sends it back as trimmed.
Collector approaches well-known dealer who happens to spend a lot of money with grading company. He does this at a large show where grading company is also set up.
WKDealer tells collector...just wait a minute, I'll take care of this.
Well-known dealer comes back and explains how grading company has made an honest mistake. Shortly thereafter, collector gets the card back in a shiny 7 slab. Because, heck, honest mistakes happen.
Probably the only time this has ever happened, though.