Just to let you know, Cadet Command probably used AR 40-501 chapter 2 standards when reviewing your condition. AR 40-501 chapter 3 are the retention and separation standards used for determination of MEB which are more lax than chapter 2 accessions standards. In other words, your unit used the more lax standards of chapter 3 when determining whether or not you stay in the ARNG. They did the right thing though. You're a bona fide ARNG Soldier so chapter 3 is the right standard to use.
Before you appeal to Cadet Command, there a few more things you should find out.
When someone has a pulmonary embolism (PE), then I start to think of a "hypercoagulable state." There are disorders that need to be looked into to make sure you don't have them. I would make sure you don't have Factor V Leiden, Prothrombin mutation, Antithrombin deficiency, Protien C deficiency, Protein S deficiency, and antiphospholipid antibodies.
There are other conditions that put anyone at risk for a thromboembolic event like a PE such as prolonged immobilization (long flight, post-surgery, etc), cancer, and pregnancy. So there you have the BCP that increased your risk for a PE. But women are put on BCPs all the time and we don't see a lot of PEs in them? What made you so different? That difference is what I'm talking about when I say you need to make sure you don't have some other hypercoagulable state. A woman with Factor V Leiden and on OCP has a relative risk of 9 times a woman who is on OCP but doesn't have Factor V Leiden.
I would say if you do have a chance a reversing this decision, you may have to wait a year after being off medicine and show documentation you don't have any those inherited disorders I mentioned earlier . Were you on Xeralto for 6 months or something like that? When was your last dose?