<p>“this scenario happened to a close friend of mine, he then had his admission rescinded by both the ED school he rejected and the RD school he deposited, it was after may 1, and he was SOL and had to take a year off and not attend any school.”</p>
<p>Glad to see that the system works. Unfortunately, if Dionysus is correct that Oxford, as a foreign university, will simply ignore the OP’s egregious breach of contract with Columbia, it seems the OP may get away with it.</p>