Yes you did. But the Helios 44-2 is a single coated lens and has a reputation of being prone to flare. My post was therefore meant to be a rhetorical question. Perhaps I should have been clearer about my intent. If you look closely at professional photographers at work you will notice that they use a lens hood much more often than amateur photographers. When you really have to get a photograph you appreciate devices such as lenshoods.
I haven't had too much problems with lens flare in the past, so I haven't bothered to use a lens hood most of the time. As I believe that's exactly what caused the problem this time, I'll certainly take it more seriously. At least now I know that the film is not the culprit.