I think they're mistaking the RAM's heat spreaders for radiation shields. Heat spreaders were common for DDR2 and DDR3 ECC RAM. Some models, like the KVR667D2D

I think they're mistaking the RAM's heat spreaders for radiation shields. Heat spreaders were common for DDR2 and DDR3 ECC RAM. Some models, like the KVR667D2D4F5/2G, have temperature warning labels, indicating that it's not a radiation shield. Such a thin layer of aluminium isn't able stop a significant proportion of gamma radiation.