Raja was told by management that he should invade the ring as part of an angle
Raja was told by AJ Mana, a wrestler working the event, that he could give Stu a receipt. In fact he was told that if anyone had any problems with it AJ Mana would take care of it
Raja is not a fan of wrestling, he is not knowledgeable of wrestling culture, nobody informed him what a "receipt" means in wrestling, other than hit him for real.
Raja told the promoter he was going to hit him for real several times, nobody bothered to explain how it was supposed to go to him.
The promotion is now trying to keep the police from talking to the wrestlers.
This entire episode is entirely the fault of Reno Anoai'i, the promoter, who explicitly told Raja he could slam Stu and punch him multiple times.
At worst you can get Raja with manslaughter. He was an outsider not sufficiently prepped on proper ring conduct. This is a case of negligence, not murder