As a Coast Guard family, I ASSURE you that there are multiple ways to become an officer in the Coast Guard if that is truly your DS's hope. If CGA is his dream, then I hope that he gets his wish. If that CGA appointment doesn't come through, though, just know that he could always go to another great university, go MARGRAD (degree from one of our 6 civilian US Maritime Academies or USMMA), DSCC (Graduating from a Senior Military College after being in the Corps of Cadets or 2 years of another ROTC program), CSPI (attending a minority serving institute) or graduate, enlist and apply to OCS. I know that it can become very easy to get narrowly focused on CGA as a means to become an officer but there are many other ways to reach that goal. It is still competitive, of course, but if his ultimate goal is to become an Officer in the Coast Guard, he can get there.
I know that it can become all consuming to travel the Academy application route and sometimes it can seem frustrating or discouraging. Keep thinking positive and, perhaps, keep the other avenues in mind, too.