Well, no wonder!! It's supposed to be the left shoulder you toss some salt over, not the right shoulder. Over your right shoulder means you'll slip on a crack and end up smashing into a mirror causing you to have 77 years, 7 months, 7 days and 7 minutes of bad luck..
a tub of salt has fallen over,
spilling it's contents on a table, one lady throws some salt over her shoulder, salt ends up in a man's eye, he is sitting by her, on a comment bubble is written "well, that wasn't so lucky, eh?" comic cartoon style