"That is true, I could just copy the module and rename it as something else and copy it directly into my script."

Don't even rename it. Dump it in any directory you feel fit and use lib.

"Plus if someone finds out that I copied it from a CPAN module, then I would be in trouble because I will be violating our 'policy' and it would be considered as plagiarism, right?"

And now you make it sound like it's a school/homework project. The module in question is licensed under the same terms as Perl, so if using Perl is considered plagiarism, yes.

"And as someone mentioned, if I 'copied' a small snippet from the web, then it would be fine because it is just 'small'."

The size of the snippet doesn't matter. If you don't know what it does exactly, the security issue still applies. I'd personally trust CPAN modules more than random "snippets".