Because they didn't test for synthetic testosterone in the other tests. They tested for the T/E ratio.
So...are the samples from the other stages still available, or were they discarded?
I still don't buy the "instant boost" effect of testosterone that some people claim. I took testosterone years ago and it does NOT have that effect AT ALL. It increases the gains from weight training, but it takes weeks and months to show results. It is not the overnight miracle some make it out to be.