When I have signed in using Oauth under accounts. 

It doesn't seem to use the SSH key generated to push.  

Steps to replicate

1. Sign into Bitbucket using oauth

2. Click copy to clipboard and try paste it into bitbucket-> settings -> SSH keys -and it will validate in Bitbucket that its already been added

3. You will still get permission denied when you attempt to push to a private repos which you have access for. Even if you try use the Bitbucket setting for downloading from sourcetree - it will still say that the repos url is invalid - as you don't have access 

The reason.. is that Source tree is using the wrong key to connect..

If I try use command line - it works correctly