No script fails from the perspective of the block chain. The external users see failure, because only the external users are aware they violated the strict partitioning of state. And thus the spaghetti of external failure becomes as intertwined as inputs and outputs from many partitions cross-pollute cascades and intertangled scripts.

Edit: the block chain thinks it is validating the block chain because it erroneously thinks strict partitioning is enforced. External users see that validation is failing, because they violated the assumption of strict partitioning by cross-polluting the state via the external I/O of the block chain. Thus holistically and systemically there is failure (from the perspective of the external users and thus the coin's market value plummets as users abandon the system due to failures).