got news for ya; almost any joke you can think of "The Simpsons Did it". I can't promise any of my comics don't come from a joke I already heard, and neither can you.
There are some variations there, but the similarity was not intentional.
Probably? Please. Both came out on the same day, but cokemirror's came out first. You can go look yourself. I mean, at LEAST wait a day or two to steal someone's joke.