I don't think it unreasonable that the consideration be given to requiring one for NVFR operations. In this and so many other cases, as soon as the pilot lost visual reference, all he had to do was switch it on.
Yeah yeah yeah, let's mandate it, effectively ending night VFR. Let's see ... cost of fitting, cost of maintaining, training to use and making sure they all work. Beaudy Radar, great suggestion
It would be easier to outlaw NVFR. The answer to all this is NOT mandating equipment.