It could be accidental drag and drop. I do it semi frequently. If you double click and move the mouse during that it can happen (one of the clicks becomes a click and drag).
Can happen in the Lister or in the address bar.
There was a fix to stop it in the address bar.
Preventing a shortcut to a folder/file being made in the same Folder seems like a logical improvement. I don't think we can intercept the event with scripting.