Thanks for this. I'm a train driver myself and I can tell you that there are plenty of lights that are not flashes and very annoying (cars, advertising, public lights, ...)
In this case, I knew the driver but in many other cases (like the ETMF also on Transpo) there are no lights in the vision field of the driver. I've been experimenting for around a year now with some friends drivers and their words are that the flash of light is the same feeling than when the pantograph is moving under the catenary.
I don't want Transpo to have troubles anyway and won't post any other night shots. I understand all the legal considerations and will act as a good citizen in the future