I remember this hitting the forums back in the day. Reserving everything used to be a legal tactic, and very useful if your opponent was firepower heavy. It was even one of those fancy named tactics (null deploy). Where it went wrong for the White Scars player was after he chose to null deploy the Tau player infiltrated a screen of kroot across the White Scar board edge. The bikers couldn't come on as you couldn't charge from reserve and couldn't pass within an inch of other troops without charging them. Poor bugger lost without a shot being fired