Honestly, it does not look like Facebook did something wrong when you read the article. A pregnant woman used a medicine to trigger a miscarriage, then she and her mother got rid of the body. Police knew that they've discussed this in Facebook messenger. They contacted Facebook and received chat messages. Then police used those messages to incriminate women according to existing law. The only problem here is that a woman could go to an abortion clinic and do it properly and legally if not for obnoxious laws in some states. But that's a completely different issue

How could someone force mods to reopen? Blackmailing? Or they just really don't want to lose control over subreddit (and possibly see it "shittified")?
I also wanted to write just how stupid it sounds and that things like that were impossible on the forums of ye olde internet - but actually they weren't, admins could do anything if they wanted, lol