No one needs to do anything. "Caveat emptor"
You bought Bitcoin knows the risks and volatility, and you pay the price both ways either in your favor or not.
well he does need to apology, he wanted to create panic so price would fall and he could buy bitcoins for small price, lots of people that trusted bitcoin had to sell it because price dropped really low and really fast so they thought that bitcoin will die
well, we cant say that he wanted to create panic as he seems to have told his own opinion and he did not tell anyone to avoid it
i dont think he needs to apologize but it would definitely be a good thing as people would be more confident about buying more btc