I'm skeptical of this, and went looking for primary sources. The Finnish tax authority website seems to have a different example:
https://translate.google.com/translate?sl=fi&tl=en&js=y&prev... (from https://www.vero.fi/syventavat-vero-ohjeet/ohje-hakusivu/484... )
"Example 1: One person has in the past bought 1,000 bitcoins for 500 euros, ie one Bitcoin cost EUR 0.5. He later bought more 500 bitcoins for 500 euros, which means that one euro received one bitcoin at that time. After purchasing, he holds 1 500 bitcoins.
He sells 1 200 bitcoin at a time when one Bitcoin costs 1.5 euros. The sale of virtual currency realizes the taxation of the change in value, giving him a taxable income of EUR 1 800 - (EUR 500 + EUR 200) = 1,100 EUR. After the transaction, a person still has 300 bitcoins purchased for 300 euros. "
"Example 2: One person has in the past bought 1000 bitcoins, with one euro receiving two bitcoins. One Bitcoin cost EUR 0.5. After acquiring, he has owned 2,000 bitcoins.
He buys goods at a total of 1,000 bitcoins at a time when bitcoins cost ten euros per piece. He therefore purchases goods worth a total of EUR 10,000.
The acquisition of goods realizes the taxation of the change in the value of a virtual currency, giving him taxable income in this case as a capital income of EUR 10,000 - EUR 500 = EUR 9,500.
After purchasing the shop, there were still 1,000 bitcoins remaining for the purchase price of 500 euros. "
etc. There's another example which shows making a loss is not a taxable event.