1. If he was in danger of dying if returned to El Salvador, and that was a known fact, then why was he not granted political asylum or refugee status? His status was in the system as illegal alien - flagged for deportation.
2. If he wishes to return to the US, then he can immigrate LEGALLY. He can travel to the first nation that he will be safe in, which could be Mexico, Guatemala or Belize. Then he's able to apply for entry in the US as a refugee, asylum seeker or plain old immigrant.
3. Just because the deportation was a mistake does not mean he gets a free pass to return. If he'd entered the US legally the first time, he would not be in this situation to start with.
4. Now the kicker -- there was evidence he was a member of the gang MS-13. He denied the allegation even though a confidential informant said he was. Part of the defense's argument is he had no criminal record in the US or El Salvador. Really? Having never been caught breaking the law doesn't mean you've never done it. It just means you haven't been caught -- yet. Weak argument. "The court granted him protection from removal to El Salvador, citing credible fear of persecution by gangs there." Um, if he was never a member of a gang, why would he be in fear of persecution by gangs there? It's a Catch 22. How can you have no affiliation with gangs but also be targeted by gangs? And persecution doesn't mean imminent threat of grave harm or death. It could mean extortion (protection money), vandalized or stolen property, etc. Persecution is vague and usually implies the reason is based on politics, religion, race, color, etc. and occurring over a LONG period. So, there's no imminent threat of death. He's got the time to apply for LEGAL entry into the US.
Persecution:
unfair or cruel treatment over a long period of time because of race, religion, or political beliefs: