Sickness equals fired

My husband was terminated last night from Amazon. He was sent home by their on site medical team after multiple days of vomiting on site and passing out on site. At one point he passed out and almost pulled down a pod. After spending time with HR they told him that they would be reviewing the footage to see if proper safety protocol was followed. He was then told to see a primary care physician and come back with documentation from said doctor. Amazon gives their employees 30 hours of unpaid time off and 20 hours of paid time off (It used to be 40 UPT, 20 PTO). By Monday (10-31-2016), he had used all 50 hours. He went to his PCP that same day where the doctors ran multiple tests and were not able to figure out what was wrong with him. They advised him not to go back to work until Friday (11-4-2016) or until they could run more tests to see what could be wrong. On 10-31, my husband took this information up to Amazon's HR team. He arrived at 5:30 pm which was the time his shift started. He did not leave until after midnight the same day. The HR staff had told him that his time would be excused and to come in the day that his doctor advised. So, this brings me to 11-4. My husband arrives at 4:30 pm ONE HOUR before his start of shift in order to speak to HR. Again, my husband did not leave until 12:30 am after talking to HR for 8 hours. He was not paid for any of this time. During this conversation with HR, they told him that he could apply for FMLA and that he would receive all his unpaid time off hours back. They would not give him his paid time off back since he had already been paid (which makes sense). After my husband checked his phone when getting to his car after speaking with HR for EIGHT HOURS, he finds a termination email from them time stamped for 7pm. This means that they termed him while he was in the office with HR and after he had already filled out the FMLA application.