Originally Posted by
Big Fau
The DM isn't just a dictator, the players "voted him into power" by participating in his campaign. If they don't like a decision they have every right to voice their opinions and try to get a ruling changed, but they effectively chose to play by his rules.
DMs are supposed to act as arbiters when it comes to rule interpretations. If you don't like a ruling, ask the DM if you can debate it after the session (if there's time). If the DM's rulings are actively detracting from the fun, leave. That's your "veto".