The drain for the roof / sunroof does go down through the A pillar, that's exactly what they thought it may be, however they haven't been able to replicate the issue ....as yet.
If they do I'll post the result to the forum for anyone else that may have the same problem in the future.
After all 2 cars in the dealership at the same time with the same issue sounds like a common problem to me! I don't believe in coincidence;)