Remember that Russia knew this was coming and had plenty of time to prepare. So, they would have been large buyers of gold (and FX)  in anticipation of getting hit with sanctions. The sanctions of course hammer the Ruble and therefore Russia could anticipate needing to defend it. Now that they have taken action, the Ruble got hit, Russia defended it with bank interventions, and so it will need to sell Gold/FX to fund those operations. (Also, it could sell gold simply to lock in profits on news it controlled). In summary, what was a tailwind to Gold in a run up to this event is now a headwind. So, it was common sense to sell the news and plug any buyers who were paying up out of fear of the news. 

yeah like I said taking profits on those huge commodity moves pre market was smart