These transmission pans are very sensitive to over tigtening. If you do, the pan will warp and or cut the gasket and leak. I did and I had a real nightmare, I had to buy a new pan.

Go under the car, wipe down everything around the trans, put a piece of cardboard underneath the car overnight and see where it's dripping from. Maybe the tech was a little sloppy filling it and the drips you are seeing are just running down the fill tube.