Probably. There will always be grey market goods as long as manufacturers put quotas on domestic customers while other countries have higher taxes and regulations - and if there are shortages. Hard to imagine that Levis had production issues. Probably more a question of the distribution network being less efficient over there than over here due to multiple factors such as cost of transit, cost of labor/regulations, import duties, and mark-ups by intermediaries in the distribution chain.
Cheaper to get 2 large suitcases, fill them with jeans, and take a cheap charter flight. Or, pay someone to bring a couple of suitcases with them.
My friend claimed the Euro value added tax (VAT) was the biggest factor in the high Euro price for jeans—but I do not know if that is correct.