Ha! This is NP-Complete, no? In practice, it probably doesn't matter but my bet is that there are some configurations that will take exponential time to see if the player should be "forgiven".
There was a Minesweeper on here that used a SAT solver, but I cannot find it at the moment. As I recall, it never had any issue with resolving the board quickly. I think it dynamically resolved where the mines would be as you played the game, and if you clicked a square that could be a mine, it would be a mine, except, I believe, when there were no open squares that were safe.