Yes, indeed. My thoughts exactly. The problem with this write-up is that there should be a second variable to store the file name so that the original variable populated by the foreach loop can still be used on the expression for the flat file connection manager.

You always want the expression on the flat file connection manager to be fully qualified. In this write-up, it is not. I agree with the approach to get just the file name to use in a data flow, I just don't agree in its use on the flat file connection manager.

If you really want to use relative paths, then simply choose the "file name + extension" option in the foreach loop and avoid the script task altogether.