I believe "Under the table" in this case means the management was unaware and customer was not billed. It's the only scenario I can think of that would in this context be on the positive side of most ethical frameworks.

Happens a lot, in many types of companies and policies, that helping the customer has to be "under the table" / "off the books" :-/

It was all for free.

> It was all for free.

Awesome. You used the term "under the table", which I've always understood to mean a cash transaction that won't be reported in tax filings.

'Under the table' means 'out of sight'. It is used to indicate money changing hands but that's not the only use.

Every single time I've heard "under the table" it means "without documentation" and is used in the sense of not paying taxes.

I've never heard anyone use the phrase "under the table" unless there was money being exchanged for services without going through the proper channels. Your understanding was spot on. This was a bad use of a very old phrase.

> This was a bad use of a very old phrase.

This seems like a bit of a stretch. Just because you haven't heard a term used in different contexts doesn't mean it's invalid. On review of the same text I may have rephrased it, but while imperfect, it's still understandable in the context.

You talk as if trying to avoid taxes is unethical.