That's strange. I think it is because the db2adutl was run successfully, but the extract failed to write the files. You can update the script the take up the rc code within the output you get from db2adutl.
Please specify the version of the DB2-server and the fixpack and the operating system details. You should expect a non-zero exit code if db2adutl fails.
If that is a currently supported DB2-version for which you have a support contract then I suggest you open a PMR with IBM to get that fixed.