It's more a thing where you see something that in the wildest sense could be interpreted as racist so you call them on it.
It has been a forum meme for as long as I can remember and I definitely said it to mates long before I signed up here too.
Yoss isn't saying I am racist and he isn't belittling the issues of race in society. It's just a flippant thing.
I think if I'd left my laptop off for days after the roof leaked it'd have been ok, I committed the cardinal sin of switching it on to see if it worked.