::Good point, and I think SN 1987A is a great example for the null hypothesis (observing something so spectacular is extremely rare, far less common than instrumentation artefacts, so you would want to make a separate observation before being confident in your results). Were you suggesting adding it into the introduction or further down the page? Either sounds reasonable to me.  

 ::I'm not sure it's the best example for confirmation bias though, since Shelton didn't actually fall for it. Perhaps one of the examples discussed here might be better - the first two, N-rays and Jacques Benveniste, are the most well-known. I would lean towards N-rays since in that case many labs reported replication of the nonexistent results. (The second is also somewhat emotionally charged today since it has to do with homeopathy.)