Like being unaware of owing £4.8 MILLION? Sure, tax errors can occur.Nonsense. Do you think she is unaware, after all this that she failed to pay tax she owes.
Many years ago, my (now sacked) accountant told me not to pay the first demand HMRC sent. Or the next, or the next. I got a red final demand and he said 'pay that'. FFS!
I sacked him off and found a reputable company, there and then.