It is quite common that players and GMs have different ideas of the outcome of actions, how physics work etc. A good GM should have a good idea of how the world works and be consistent in implementing cause-and-effect. Sometimes you may need to communicate to players in advance exactly what would come out of an action if they seem to be unsure. The same goes for social situations. Some GMs have a very weird idea of how people / things react and it's a common breaking point for groups.