What can 'instantly' possibly mean in this context?

"Before the transaction with the State is legally considered complete and the taxpayers liability settled" would seem to be the relevant thing.

The taxpayer might lose in this case, but the State would not (and, the risk the taxpayer faces is pretty much the same risk as they would face holding money they need to pay taxes in bitcoins whether or not there was a standard payment processor for bitcoin-to-pay-taxes for the state.)