Um ok, what type of payment? what type of failure (duplicate, False-flag for fraud or sanctions, NSF (when funds present)? what rails? I went through some scenarios and the interviewer, who was a contractor, became a tad belligerent. I ended up going through some very common scenarios, but didn't understand the interviewer's comments on whether that was what they were looking for? He would put it back on me "do you think it's enough?".. bizarro world.