Please review this email that I received from a former colleague. Note that this is the exact email I received, so any typographical and grammatical errors were found in the original communication.

At will employee, 58, sales, hasn't sold a loan since he's been here (month or two), doesn't seem to be working out. Two weeks ago, he took off 4 days b/c of a back problem. He gave us a Dr. note for that. Since he's been back, he has been leaving earlier and earlier each day - yesterday 12:45. Today, he called out entirely. He provided another letter from his chiropractor saying he has a back condition and sitting for long periods at a desk is painful. We wanted to let him go before this came up. Now, we are concerned that he will say we terminated him because he was injured (he was not injured at work, mind you). I think we can let him go because he is at-will. Anything I'm missing?

Please identify and potential concerns you may have with moving forward this termination. Identify the relevant law and the basis for the concern. Note that there are a number of obvious facts, as well as a number of facts that are intentionally hidden.

1. identify and explain the relevant law;
2. identify the facts from the hypothetical situation that might support an employment discrimination claim or might suggest the employer's conduct was based on a legitimate business need; and
3. identify the facts that are intentionally hidden as way to illustrate an understanding of how the laws might apply to a wide range of situations that may arise in their own workplaces.