You are correct that it is a match 3 to win. In the rules it states:
After the game has been played to a state of completion, you will be presented with a instant win game screen. You will then be prompted to uncover three checkers. If the three checkers match you are an instant winner, subject to verification. The screen will reveal if you have won a prize, and what that prize is. Any unused instant win game plays at the end of the Promotion Period are forfeit, have no value and cannot be played. Potential winners of the Instant Win Game will be provided directions for validation. All potential winners are subject to verification before any prize will be awarded. Administrator is responsible for the functionality of the Instant Win Game.
Perhaps you can post on their FB page to get the answer you are looking for.
