Pretty sure this won't be reason at all. Though this news is old but I would like to add my point of view on it. I really think that miners keep selling their bitcoin's as soon as they get mined because they have to cover up their expenses of electricity and maintaining cost so they need lots of money for that purpose. I'm sure they can't keep waiting all the time for bitcoin price to spike and hence they keep selling it once they get it confirmed. Or they could be selling at least 50% of the bitcoin and thus it decereses the count of coins with them. This may not dump it that badly as gox situation did. :-D