Maybe these people wanted to buy more of it bitcoin at a very cheap price or perhaps these people wanted to invest for the first time and it will be in favor of them if the price will really fall down. Others might also be wishing that it will happen so other alt coins' market price will also fall down so they can buy it at a very cheap price too.
Many people expect the price of bitcoin to fall, because they target low prices to buy, with price calculations going up again, so they get a lot of profit. They will create situations where bitcoin gets negative sentiment, they do it because they have a lot of capital and are greedy.