I think they are saying Alex Jones is responsible because his followers ended up stalking and harassing the victims parents. One could argue he never directly said to do that so it isn't his responsibility, but he also has a big platform.
I’m not trying to make some gotcha argument that you can cause your followers to make death threats and therefore you had no part. I’m making the case that Alex Jones is an idiot who says things about water turning the frogs gay, and under no reasonable interpretation of his actions or beliefs can I see that he intended to cause death threats to occur.
Whereas Bernie immediately denounced the shooter and reached out to Steve Scalise. Steve does not blame Bernie for having a deranged fan (https://www.newsweek.com/steve-scalise-shooting-bernie-sande...). Bernie did not imply Steve deserved to be harassed or shot. He has, in fact, asked his supporters to back off (https://www.rollingstone.com/politics/politics-news/bernie-s...).
These two things are obviously not equivalent.
It's still the case that he changed his attitude too late, only after some of his listeners acted and the escalation became real.
This is an interesting point, because had he done that it could be used against him as an admission of guilt.