Andy's answer makes me think of something that's happened to me on more than one occasion:

I write a small program. It has a bug. I fix the bug, run it again, and the buggy behavior continues. It shouldn't. So I add some print statements just to debug it (and/or maybe to prove that it should work), and then it works right. So I take the print statements back out, so I'm left with the same program I had before I added them, and it continues to work correctly.

I've witnessed other things that are unexplainable, depending on what priors you have and hence what kind of explanation you'd accept. They certainly don't make sense under the popularly accepted physicalist, rationalist view of the universe. For example, one time there was a girl sitting next to me in a mental hospital trying to talk and slurring all her words, not being able to decide what to say, etc., and there was a small ball of white light dangling in the air just beyond the tip of her tongue. Personally, I would explain it as one of her chakras, one related to speech, being under so much pressure that it starts emitting visible light. I think I know why this was the case, but I won't go into it.