push(@errors, grep (/ERROR|ORA-ERR|Fail|Unable/i, $_));
You're either confused, or very clever.

Let's try:

perl -e 'push(@a,grep(/bra/,"abracadabra")); print @a;'
abracadabra
perl -e 'push(@a,grep(/bar/,"abracadabra")); print @a;'
(no output)
[download]

Wow! It works.

My proposed solution for your problem is to put a line like

next if /ORA-\d: unique constraint \(.*?\) violated/;
[download]

just before the push line.