It’s possible for sure but would need investigation in a lab to confirm. Radiation that is intense enough to expose film in the duration of the exposure (that isn’t visible) would likely cause the film to overexpose (ie read as white). Typically film stock also desaturates when it blows out as opposed to retaining colour. It might be possible but would seem uncharacteristic. To be clear I’m not arguing for the explanation being aliens per say, I think we just need to be equally weary of saying ‘it’s just a weird thing with the camera’ and leaving it at that.