$40 in a next few weeks is not possible IMO. He probably just wants to create some fear in the current market.
Never say impossible, anything is possible in this world, especially in the crypto world. Half a year ago, I and many others did not think to see the price for Ether even $200, not to mention even $100.
You are right. Everything is possible in crypto. But the most possible scenario nowdays is uptrend and ETH will not going down more I think. A lot of big thing for crypto will be in the beginning of next year (such Bakkt platform or Fidelity platform). And ETH will have a hardfork with a lot of updates between 14th and 18th January 2019. So now is a good time to buy cheap ETH and prepare to next bullrun.