No excuse, but it would be interesting to know all the mitigating circumstances, if any.
We all know cases of air rage are increasing: closely correlated with increased security clearance times, ever-reducing seat sizes, lack of meaningful customer service etc etc etc. There are two sides to every coin. Keep pushing down on standards and you will inevitably get blow-back.
Still, defecating on a food service cart takes some beating. That's one image that will take time to forget.