I've just come across the following and was wondering if this might be a bug.
When using the SharePoint UI it does not allow you to create a list with the same name. However, if I create the library with a unique name and then go back and update it with the name of a list that already exists in the site it allows me to apply the change. The reason I ask this is when using CSOM it has the following method which only returns a single value :
Should you be able to do this? If you are why does it not allow you do this when creating a library?
I've tested the following on SharePoint 2010 and it does not allow lists with the same name. Will test the other versions today.