On reading your post, I wondered once again, "what exactly IS 'sushi grade fish'?"

I got conflicting answers from the Whole Foods sushi chef (who was trying to persuade me to buy HIS sushi, with a 'don't try this at home, kids!' sort of mentality...like it was just too complex for me) and, on the other side of the store, the Whole Foods seafood department guy (who was persuading me to try it).

So I found this article. Thought you might like to know. Note how cold the fish has to get to destroy parasites:

"The only concern any inspectors have is referred to as the parasite destruction guarantee, which is accomplished by 'freezing and storing seafood at -4°F (-20°C) or below for 7 days (total time), or freezing at -31°F (-35°C) or below until solid and storing at -31°F (-35°C) or below for 15 hours, or freezing at -31°F (-35°C) or below until solid and storing at -4°F (-20°C) or below for 24 hours' which is sufficient to kill parasites."

http://www.sushifaq.com/sushi-grade-fish.htm

I don't think my freezer gets this cold. Next time, I will ask the Whole Foods management if their fish vendor follows these freezing precautions.