If such a thing happened by accident, you should not get 20 years. If you did so intentionally wanting to cause harm, them perhaps you should get 20+ years, because that would be an act of terrorism. If someone got killed, you should probably not get your freedom back.
Journalists need to always mind the context and emphasize the likelihood of what will be the outcome. It is not really truthful to bluntly state he faces 20 years. If he were to actually get 20, the legal system would obviously be severely flawed. There are murderers that get 20 ffs.
Edit: Also the post says up to 20 years .. not sure why you've become fixated on it being simply 20. People dropping planes out of the sky for likes need to be made an example of imo, and I personally would be happy to see him locked up for life as a deterrent to others. The lengths people are going to for likes is frightening.
The biggest problem with deterrence is it relies on people not thinking they won't get caught. Everyone thinks they won't get caught.