There were a few big btc buys before the silk road sale, so unless someone was stocking up on kilos for President's Day, I think it was one (or more) speculators trading on the news of the event, rather than the event itself, that caused the rise in price. Correlation != causation.
Here's the 16k btc buy that kicked it off on Feb 2nd (this is a one minute chart):
Which seems like a smart play: the speculator/manipulator bought their coins, driving up price, then presumably sold them off at inflated price to silk road users before the later fall. It's impossible to know just how much of the rise was due to the silk road sale, let alone call it proof. I doubt it really had much effect besides as a vehicle for a speculator to make a play. The short-term movement of the market is dominated by speculation, not fundamentals.
