If she wasn't willing to take the boxes out for you to inspect then they were almost definitely fake. HK people like to handle the goods up front so they can check them. Any shop that won't let you examine a product you want to buy will always ring alarm bells with me - be it 100% fake, an empty real box, or you ask for the real item and they switch it out for a fake as you buy it.
Definitely better to be safe than sorry in that case.