"Help me understand why the RCC tolerates the hiring a witch/Wiccan/pagan at one of it's universities to help teach religion."
The lady in question is not teaching religion, but rather the psychology of religion.
Your question is still a fair one, even corrected, but accuracy in these things avoids misundertandings.
sitetest
It isn't a Catholic College despite its name. To be Catholic one must keep the Bonds of Unity in Worship, Doctrine, Authority. A College or University is supposed to comply with the strictures included in Ex Corde Ecclesia and promise to maintain communion with The Magisterium, hire Catholic teachers and teach Catholic Doctrine.
These clowns clearly don't - many universities calling themselves "Catholic" clearly don't but the Pope can't close a college and the local Bishops refuse to do their duty - they are to assure Catholic schools in their Jurisdiction are Catholic but they refuse to act - so, we have insane stuff happening like this witch story so the laity have to do their duty and not send their kids to this college unless the laity want their kids educated by this bathetic broad.