How do the drain tubes connect with the sunroof?

[rooroo]

I've had water infiltrating the passenger A pillar when raining. The water then runs down to the front passenger foot-well and accumulates.
A search shows common issues with clogged sunroof drains. In my case water was puddling in the front passenger side on the opened sunroof so I blew compressed air from the drain end under the car. And then noticed that the water in the sunroof drained. I poured soda water into the drain of sunroof and it drained easily and I could see it come out of the bottom of car with some gunk. I poured some more until only clear fluid came out.
Problem solved! or so I thought...
I looked and noticed that water/soda was still flowing down the inside of the A-pillar. I have opened up as much of the headliner and a-pillar liner to be able to see the drain tube. but as it turns away from the a-pillar and goes towards the sunroof I lose my visual and tactile ability to follow it.

The only way the water is still coming in (as far as I can figure out) is if there is a failure at the point where the drain tube connects to the sunroof. But because I can not see it, I don't want to go through the work of removing the entire head liner without knowing how it connects. Is it a simple "insert" connection where one tube is larger than the other? or is it one piece from the drain, is it molded as one piece?

Any one have any ideas?
Thanks in advance.

Rui