That's merely the marginalists at the WTO struggling to fit their beliefs that value is subjective and unkowable into the reality of commodity production.
More manufacturing capacity coming online to return the price to normal is not dumping, it's how markets are supposed to operate.
Dumping would be e.g. if China used subsidies to sell DRAM at a price below what unsubsidised manufacturers can sell at, in an effort to push them out of the market.
So some common sense is required: yes under normal circumstances selling below the market price is dumping, but when the market price looks like a vertical line because of a sudden shock then you can't really take the market price too seriously. Mostly the price of DRAM is not set on the open market but is negotiated via contracts between the major players so there isn't really one price of DRAM at the moment. If you're a big customer like Apple you can get a price that is completely different from what you or I can get fighting for scraps on eBay.