It is not written within snooker rules that you cannot foul. If you do, you just receive a points penalty. In sone variations of uk pool rules a deliberate foul can be called and the player penalised the game, but not for snooker.
In professional snooker there is the "miss" rule, and three misses on the same shot concedes the frame. There are two problems in FoD - firstly this is not considered to be a professional game, and secondly a computer will have a difficult job in deciding whether a "genuine attempt" was made at a legal ball or not as per the rules. What would be interesting is if the higher rated players could play this - where if a ball is missed when not snookered or by a long way if snookered, then a miss called. Maybe the rule could be implemented when two brown ratings or above play each other? I don't think it's a great idea on a PC game, but it would be interesting to know if it could be made to work.