Your Dad needs to seek help from an attorney or call the Department of Labor or the State attorney general and discuss the matter in detail just to make sure that all his rights are protected here.  But in answer to your question about sick time being counted against FMLA time,  it is my understanding that employers can require employees to use sick time, vacation time or any other personal time up before using any time provided by the FMLA. This paid leave can be counted as part of the FMLA time period if the employer properly notifies the employee in writing of this decision. What constitutes proper notification remains to be seen.  Please get help.  Good luck.