Just because testosterone levels rise, this does not necessarily mean that DHT levels rise as well.
DHT is made from testosterone by two enzymes. Even though testosterone may rise, your enzyme levels may stay the same, and DHT production may stay level as well.
Consider this... there are people who are losing their hair from male pattern baldness, and may have naturally low testosterone levels in their blood. How is this? Well, their bodies may have high levels of the DHT-creating enzymes, so that even a little testosterone is sufficient to incite hairloss for this particular person.
Then again, you may have a third person who has low testosterone, low DHT levels, but is losing his hair like crazy too. How could this happen? Well, maybe his hair's sensitivity to the effects of DHT is higher than ours.
Not everything in the hairloss process is perfectly correlated. There are lots of different pieces in motion, and it is fairly complex.