This requires to assume that we all see and believe this. Right now chinese speculators can bribe a small pool to generate 10 consecutive orphaned blocks and start spreading FUD that someone tried to attack Bitcoin. With intention to buy cheap coins.

EDIT: Forgot the obvious resume. https://en.wikipedia.org/wiki/Plausible_deniability guarantees that a real attack will likely be not noticed, people will just spread the idea that it's a fake attack.