I would bet the schedule didn't allow much time to doing subsystem level test with on-board computer, so everyone went to the big test praying for the best. Th

I would bet the schedule didn't allow much time to doing subsystem level test with on-board computer, so everyone went to the big test praying for the best. That or inexperienced programmers were involved, assuming they were not scared of modifying memory addresses directly. As for the safe-mode, if it happened maybe you could say you were randomly injecting errors in the memory during runtime and spacecraft entered safe mode as expected, would not be far off from the truth, just do not mention it was unintended :)