Re: Ignorance of the law is not a defence...
As much as HMRC would not like this to be known, HMRC whilst an agency of government, it is not a court of law. Only a court can determine if the law has been broken.
The situation Aria finds itself in now, is that HMRC has determined that tax is due. This is it's purpose, it is the collector of tax. HMRCs determination however has no more legal standing than an opinion. It is a very highly regarded opinion within government, but it is still simply an opinion. If HMRC wishes to enforce it's determination, it must get a court order to do so, i.e. Aria must stand trial in court for tax evasion.
At this point in time today Aria is innocent of all charges (because there are non legally brought yet), and HMRC is simply following HMRC procedure that in theory is supposed to save the courts time.
At some point HMRC having exhausted all other avenues of revenue collection will take Aria to court. Up until this happens, the burden of proof at each stage of HMRC process is upon Aria to prove it's innocence. Again I'll say that HMRC is not a court, so the normal burden of proof such as innocent unless proven guilty is irrelevant at this point.
Once a court case is brought, the burden of proof changes. HMRC has lost many VAT carousel cases simply because it cannot prove beyond a reasonable doubt, that the defendant wilfully committed tax fraud. By law, the burden of proof is placed upon HMRC to prove it's case, not Aria to prove it's innocence. However, if Aria accepts HMRCs determination before a court case, and pays the bill. It cannot appeal later regardless of truth.
I believe that El Reg is misleading the average-Joe reader via carefully crafted headlines into believing Aria is committing tax fraud. At most El Reg's actions have successfully resulted in a situation that non-criminal tribunal cases (i.e. procedural cases that if contested eventually lead up to a true court case) should be performed openly and not secretively and can be reported about.
I could go on for another few pages but instead:- TLDR. Aria are at another step in a long line of HMRC processes designed to get them to part with their cash prior to an actual criminal court case, in much the same way that dodgy debt collectors persue you relentlessly, constantly hoping you pay before a court says you don't have to.
Oh and at some point, a court decide that this process should be open to public scrutiny, and El Reg have taken credit. When did El Reg move to San Francisco?