A back injury on a field march ended my ROTC career back near the end of GW1. I fought like hell to stay in, but hte army docs would not give me a waiver for a previously unknown structural quirk in the low back (I have an "extra" vertebra or transitional S1-2 joint, not a fun thing with a 80 - 100 pound ruck on when your legs go numb and you lose feeling in them). ANyway, I got medically disenrolled and then got a letter ordering me to Active duty for 2 year. Problem was that with the back condition I could not pass a physical, so the Army was stuck - either I get a medical waiver from the Army docs and they let me finish ROTC or I am medically inelegible and I get out. Tokk afew letters and a doctors deposition, but they eventually worked it out.
Really crushed me as I was only a few months from commissioning when I got hurt. But I got over it.
You also should find in that contract the notice that anytime in the first 2 years of service as a Officer you can be dropped if you develope a condition that would have made you inellegible for commissioning. Once you hit 2 years they have to board you out.
All this is circa 1990, so it might have changed.