Can a post-dle-backup script invalidate the backup?

Hi,

If a backup application succeeds (exit 0), but then a post-dle-backup
script runs and detects an error, does the backup get marked as failed?

Example: the amlvmsnapshot script runs at pre-dle-backup and creates
a snapshot, runs again at post-dle-backup and removes it. At the time
of removal, it checks the size usage of the snapshot. If it reached
100% during the time the backup was running, it is bad news, and one
must not trust the backup, but only the post-dle-backup script detects
this, even if the backup application seemed to exit normally.

-Chap