Why are nursing professors forced to work more hours than English math or science professors?

A local dean requires more hours from my wife without extra pay (overload) but my wife has the same contract as any other 9 month employee at this college. The HR dept has been informed multiple times but the President of the college shuts it down every time. This dean uses ridiculous intimidation and retaliates with passive aggressive methods and creates more work in the process. The staff is for the most part, afraid of her because she consistently gets the ones who dare to stand up to her or complain on her. I personally know about 25 people who have taken early retirement or quit because of her vindictive nature and there are more on their way out the door. My wife is 5 years from retirement but is going to take a cut and early retirement because of the hostile environment that this woman creates. My wife works a minimum of 60 hours per week. A math professor that we personally know works 30 on campus and 10 at home. My wife works 38.5 on campus plus clinical hours and home hours. The only difference in the pay is because of market value. Please advise. Thanks.