Your assumption is correct and I'm not really sure why you are surprised by this diagrammatic outcome, as the program is simply doing its best to display a situation where there are multiple family relationships between two or more people.
Every family history program I've used, by default, displays complex/multiple family relationships in a very similar way, although some have introduced methods for users to choose to hide any duplication from view in charts/diagrams. Obviously what is hidden has to be down to the user , as it would be wrong for the software to automatically choose which of the relationships is most 'important' to display, which could change according to what the user wants to see displayed at a particular time. I presume that is what Renee is referring to as a possible future development "on the enhancement request list".
Charts/Diagrams can, of course, become far more complex as Trees grow in size, especially for people who's families have lived in relatively small communities for several generations. Then there's the oldie often quoted as an example of more complex relationships: https://en.wikipedia.org/wiki/I%27m_My_Own_Grandpa -Try creating that situation in a Test database and have a look at the Chart if you're ever bored.