Ugh, a rename of a branch in SourceTree can seem to create a second, duplicate branch at bitbucket.org.

Inside of SourceTree one may easily right-click on a branch and pick options for delete and rename to delete and rename, but the renaming has this shocking side effect. Is this a bug I've found? (using SourceTree 1.9.13.7)

 
 

Addendum 8/2/2017: This has not happened to me a second time.