Extra-virgin olive oil ought to be flammable enough to keep an oil lamp burning. It will also burn without producing any noticeable smoke. So, if your olive oil will not keep a wick lit (or if it can, but produces a lot of smoke), you can trust that it is fake olive oil. However, other oils can keep a wick lit, too.
There are three terms we need to define: Holland, the Netherlands, and Dutch. In Old English dutch simply meant “people or nation.” (This also explains why Germany is called Deutschland in German.) Over time, English-speaking people used the word Dutch to describe people from both the Netherlands and Germany.