The problem, from what I see in the picture. Is the mulled units are leaking. Who knows? It could be bad coverage or sealing too. If you're going to document stuff take more pictures. How about the outside or even a little context to the nature of this post would be helpful as well. What exactly are you doing?
We have over 2000 pix of this project;we are providing arbitration/litigation technical support involving building construction defects, window functionality and indoor environmental problems caused by massive water intrusions in a new home on the water. These intrusions are a result of improper construction of aspects of the building envelope and leaking windows (poor design and installation and potentially underrated for this location).
I can tell you this because I really work in the business. These problems, in most cases are the construction company's fault. Good builders are hard to find anymore. You should go after the construction company that put the house up. Water doesn't get into a house horizontally in most cases. The leak is because the builder cut corners and hurried to make a buck or two more. Expose the companies who build like this.