Those laws of probability only apply if you were to say reverse engineer about 500 to 1000 of those items, and in that case it should come out to be 1 out of 5 tries on average for a success. But if you want to break it down on a single individual attempt, there is a 1 - (1024/3125) or about a 67% chance of getting a success in your first five tries. Honestly the probability of 10 failures is high enough that I can say it is not an outrageous result for it to happen every so often. Basically one out of every three items should take more than five tries.