Hi Brian,
Default timeout value in Timeout Property is 30 seconds. Timeout value specifies how many seconds must pass without any activity between wodSFTP.NET and remote server before wodSFTP.NET will autodisconnect from it. You can change that value any time in timeout Property.
Can you please try to increase timeout value and let us know how it goe?. Maybe you are experiencing some other issue here.
I'm not sure what do you exactly mean by rollback if the file does not fully load . You can resume file transfer from position where it broke if you set Resume Property to True. You can also delete file using DeleteFile Method.
More help for Resume Property you can find here:
http://www.weonlydo.com/SFTP.NET/Help/WeOnlyDo.Client.SFTP.Resume.html
More help for DeleteFile Method you can find here:
http://www.weonlydo.com/SFTP.NET/Help/WeOnlyDo.Client.SFTP.DeleteFile2.html
Let us know how it goes.
Regards,
Drazen