Honestly? Shoes a little over the top for school, but that's a taste thing, not a rules thing. I had teachers and faculty members who wore more 'disruptive' female clothing, and a dean who wore the exact same style of shoes (even while she was pregnant and still working).
Stupid stupid stupid. Denying someone an education because they have the guts to express themselves. (Which is what sending someone home is, it's denying them their education.)