Here is one example:

http://www.cnbc.com/id/100630626

http://www.ibtimes.com/why-did-gold-crash-april-2013-compute...

http://www.cnbc.com/id/100665045

If you had a bunch of puts, sufficient dumping might be enough to create a panic, and then the puts would be worth more than the loss from dumping.

If you short the stock I believe the dump and subsequent dump would be in your favor.