Excellent! Less competition for me, HAHAHA!!!
But seriously, I submitted my application a few days and the confirmation included an email address -- email@example.com
-- to contact if any problems arose.
I would try emailing them since they are not affiliated with the university.
I imagine that if this is a serious problem that affects a lot of people and Caltech does not notice until after the deadline, they would just extend the deadline to accommodate everyone affected.