I'm going to have to agree with Suzeeq.The fashion industry does borrow designs from each other all the time.This is why in the end I didn't decide to go to fashion school, but instead decided to do what I knew and figure the rest out. It usually goes from runway to various levels of knockoffs. You get your Bloomingdales knockoffs, Nordstrom, Macys, JC Penny and eventually it all goes down to Wal*Mart, Target, and Kmart.Usually the cheaper alternatives are somewhat simplified versions of the original runway inspiration.My fashion design teacher in high school actually copied sewing patterns for a living.Her job was to create knockoffs for Nordstrom.
Similarly,people on ravelry copy their patterns from knitting books and vogue all the time, usually presenting them as their own original idea.
Ever heard of the quote "Everything that can be invented has been invented " ?