I believe you are confusing them having limit orders in the book on both sides with them having places both ways. In 1 instrument you can have a place at any given moment - the web position of the orders, even if you purchased multiple times and both sold. The orders will just average out to provide the true position to you.
You're probably thinking with a MetaTrader like mindset of multiple opened places.
This is a matter of defining the word position. You're using the retail definition, I'm using the appropriate definition....