In https://bugzilla.redhat.com/show_bug.cgi?id=1317047, the download of the file from the Satellite server fails (503) but the Capsule goes ahead and creates a 0 byte file. There doesn't appear to be any error checking at all. Looking at the code confirms this:

https://git.io/vPVhw

Moreover, if I run that command with a bad file, I get a file on the filesystem with 0 bytes!

$ wget --timeout=10 --tries=3 --no-check-certificate -nv -c http://example.com/bad.file -O bad.file
$ ls -al bad.file
-rw-r--r--  1 jomama  wheel  0 Oct 13 15:13 bad.file


So not only does the Capsule not capture and report the error but it also creates a 0 byte file (as if the download succeeded).

That is BAD!!