Tap once or twice on your sarcasm detector and see if it's running. It might just need calibration since it didn't pick up the tone of the message or the emoticons.
In the worst case, a complete overhaul might be required.
You might want to test it on this message and note the result.
Here are some emoticons to complete the test: ;) :) :D
"No you can't just "sed s'/Red Hat/CentOS/' (someone always offers that)"