There is a lot of pressure to reduce staffing in these 24 hour units and anyone who has worked in them knows the boredom of the 1am to 4am hours and it is tempting to let people officially or unofficially 'nap' somewhere. But I always felt a little nervous that something like this kind of incident could occur. In some cases the person with the problem is, because of the problem, unaware that they have a severe medical issue. So a panic alarm will not do much good at all and the FAA idea for dual staffing but only till midnight shows that they have no concern for the individual controller but instead for the operation of the airport. I hope she recovers but half an hour delay in getting help for a stroke is a long time.
Perhaps the only way to get a reasonable response from the FAA would be to point out that a security response to the tower after 911 calls from aircraft should be a lot faster than 20 minutes.