Networker Oracle Restore using full backup and level 1 backup

Backup of Oracle databases are done with Networker and complete succcessfully. Full backups are done once a month, Level 0's are done on a weekly basis and Level 1's are done daily.

A restore was tested ,using a timestamp of a time just after which a level 1 backup was taken. The restore was successful, but it first recovered the Full backup which was taken on the weekend before, since it was the end of the month, then it used the Level 1 backup which was taken on that day, followed by an archive log of the next day's backup.

From the Networker documentation,Networker Module for Databases and Applications, "A full backup cannot be the parent of a subsequent incremental backup.Incremental backups cannot be dependent on a stand-alone full backup."

Also from Oracle documentation," A full backup cannot be part of an incremental backup strategy; that is, it cannot be the parent for a subsequent incremental backup."

Can someone please explain why the restoration used the full backup and then the Level 1( incremental ) backup, yet according to the documentation, this should not be possible.