Sounds like a classic "That's funny..." moment, to me.
If you're doing something that involves using machined chunks of silicon in the path of gamma rays for some other reason entirely (perhaps they're to neutrally mount some other material that you're irradiating), and then you find that your gamma ray detector isn't getting any rays.... after uttering the words above, you mess around with the layout and discover that removing the silicon sorts it. Rather than going "phew" and carrying on with the original experiment, you say "that's very funny..." So you put the silicon back, move the detector around, move the silicon around, discover silicon refracts the gamma rays. "Eureka!" follows.
Science happens like that all the time, the serendipitous surprise is a major component of the fun. As are the celebratory beers.