Yes, I thought so too at first. But you turned out to be a cunning bug. You could have easily pulled something like that, and then said, "No, I'm not stupid enough to do that." Which is exactly what you're doing now.
Well, with such a theory, you can come up with anything. Tell me, are you denying that I was in isolation on the 4th night? Considering the data from the 3rd, 4th, and 5th nights, who do you think I could be from the negative suspects?