When you double click the Draw Step icon it draws a card and proceeds to Main Phase immediately, so that may have been what happened.

In other news, I run into people like this every now and then who don't understand the way the banned & restricted list works. I was trying to find a link to the official list, but Google failed me before he quit:

dmN shuffles library
dmN shuffles library
<Dan> hey
Dan shuffles library
Dan shuffles library
<dmN> hi
Dan shuffles library
Dan rolled a 1, using a 20 sided die
dmN rolled a 8, using a 20 sided die
It is now turn 2 (dmN)
It is now the Beginning Phase, Untap Step
dmN draws 7 cards
Dan draws 7 cards
dmN plays Mox Sapphire from Hand
dmN plays Island from Hand
dmN plays Mox Sapphire from Hand
<dmN> End my turn
It is now turn 3 (Dan)
It is now the Beginning Phase, Untap Step
<Dan> why do you have two mox sapphire?
<dmN> no restrict
<Dan> it's restricted in vintage
<dmN> restrict : i cant have two
<dmN> can
<Dan> it actually means you can only have one copy between main deck and sideboard
dmN puts Mox Sapphire to Graveyard from Play
<dmN> End my turn
Dan untaps his/her permanents
It is now the Beginning Phase, Upkeep Step
It is now the Beginning Phase, Draw Step
Dan draws a card
It is now the Precombat Main Phase
Dan plays Black Lotus from Hand
Dan plays Mountain from Hand
<dmN> opa
<dmN> banned you can
<dmN> ?
<Dan> one second
<dmN> and restrict I not?
<System> Player Lost

This was an awesome tournament, thanks to everyone for the good games and sportsmanship, and especially to Ron for hosting.

EDIT: My misplaced deck appears to have been found, so if this is the case then it will only reaffirm my belief that the Vintage community is full of awesome people. Thanks guys.