Instead of engaging the critics, they circled the wagons, took on a siege mentality, went double down on publicity promises that they were going to deliver their drug, started acting extra arrogantly. And, more privately, they acted like cornered wolverines with their critics - rejecting every suggestion and being nasty, blaming the critics for problems of their own creation.
This is a very apt summary of the dangers of the siege mentality. I really want HF to pull it off and turn this around, but unfortunately most companies don't have the skillset in house to be able to do this. It's very difficult. When you're in the siege mentality, the default thought is that it's a storm that will blow over. "Okay, everyone will stop as soon as we ship/ship second batch/lower prices/keep not saying anything/fire a few people" but the storm never blows over. The only thing that fixes it is what you said earlier - transparency and reasonable compromise - and that's hard to switch gears to when just keeping the business alive is a struggle. (Most startups are in starvation mode for a few years, that's not specific to HF)