Your guess was right. I get the same error message even when the Hat is off.
The output of uname -a is:
pi@raspberrypi:~/unicorn-hat/python/examples $ uname -a
Linux raspberrypi 4.1.19-v7+ #858 SMP Tue Mar 15 15:56:00 GMT 2016 armv7l GNU/Linux
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New Unicorn Hat not working
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