Playing illegal moves is accounted for in rules. Depending on which rules you play by it can be an immediate forfeit, or involves redoing moves and adding time for the opponent, possibly with forfeit if repeated. As such, the article opted for one of the strictest possible rule sets. You can reject the interpretation he gave, and the outcome under those rules would still be the same. If you were to pick a more lenient ruleset, it's possible it would've come out with an even higher ranking.