Alley,
As a supporter and participant of our system of higher education, I hate to say this, but it is clear that college and universities can generate an endless supply of shameless, bureaucratic stupidity - especially if it lines their pockets. If you run into this, always politely press your case further up the hierarchy and do not back down. A letter to the college provost, dean, or president can be helpful. See if you can get Davy's doctor to write it on his behalf. Of course, as folks here have said earlier, document names, statements, and conversations and times.
Seek help with the school's student advocate office if there is one. Although such services are limited to what the school will allow them to do, they can often get you and Davy to the right place faster, rather than run from office to office trying to plead your case over and over.
It also helps to stay on top of the process. It can easily get forgotten in the shuffle and then you hear that it's too late to do anything. Call every day if necessary.
As was mentioned earlier, you should take depression seriously. Let Davy's doctor know about it. I was nearly killed and badly injured in an accident when I was only a few years younger than you and reeled about my newly discovered morality for weeks. I can only imagine what Davy's going through.
K