I think most of us that joined bounties in the year 2018 had experiences like that. I was also expecting that it would happen because of the lock-in period but I guess the investors are just for short term and they will sell it after listing because their bonuses are already enough for profit taking. ICO bounties should do buybacks or Eth/btc payment so investors would not get the fear of dumping from bounty hunters.
They really need to look for a way of systematically controlling this dumping issues going on in the market, other than blaming it on hunter but I guess they were just doing try and error to really determine where the dumping is coming from, and now that they have seen that bounty hunters makes no significant impact on the dumping, they will let us be.
One thing about dumping is that it will always happen anytime, whether now or in future provided the purpose of putting in money into that project is to get profit and many investors dont care about future profit but they are satisfied with whatever little profit they get once the project enters exchanges so that they can move on to next project.