Without reading the other replies and being biased by them, I would give them a Game Loss for Deck Decklist Error for having a 58 card deck, as is clearly stated in the Total column in addition to the number of cards adding up to that number.
In addition I would educate the player about the purpose of decklists and show them how to fill one out properly so that we can quickly understand a decklist when we come across it. I would fix the decklist by amending the 2 missing cards or by allowing the player to add two swamps, depending on what exactly the error that caused a 58 card decklist was.
Edit - after reading everything over and recounting it several time I finally counted 60 after counting 58 three times, I hadn't actually noticed the 5/3 error initially, but even if I had got 60 I would find the player when I had some downtime and explain to them not to fill them out like this.
Edited Matthew Turnbull (Feb. 27, 2014 02:59:57 PM)