E&O is for cases where an error or omission caused damaged to you, resulting in you paying MORE than what it would have been.

I had a bank, deducting a tax escrow, but DID NOT pay the taxes on time, resulting in penalties. They might be covered under E&O. A lawyer not sending in paperwork on time resulting in you losing a case would be another.

In this case, it appears you would be paying exactly the same amount, though years late. You derived some benefit where the money was in your pocket all this time. You did not incur any out of pocket expense or damages, over and above what you are supposed to pay.