Most likely, they were errors because the file is compressed with gzip.
Typically, ".tgz" means "tar"ed and "gzip"ed.
Try:
gunzip -c blah.tgz | tar xf -
If you want to see what is being "untar"ed, add the "v" option:
gunzip -c blah.tgz | tar xvf -
Then again, it seems...