In the first place, dumping its price in the market was very inevitable and unpredictable. That's why they called volatile, where the price could get up or down at anytime depending on the buyers or sellers. Especially, if the demand is getting higher rapidly while the supply is limited the price has a chance to increase for sure but if the supply are too high while the demand is too low, it means the price will go dump for sure.
Yes and when it happened at the same time after bounty or airdrop was over, some bounty hunters take it as an intentional attack like OP. We need to understand the market, especially for a new coin after bounty or airdrop phrase is very vulnerable to dump. Cause it still young and lacks investors to drive up the price.