I read an article somewhere that said most "hitmen" who are available for hire (i.e. those who are not exclusively at the service of a drug cartel or something) have no intention of actually killing the target. The client can't sue a hitman to get their money back if the target turns out to be alive. So the crime might be more akin to fraud than attempted murder.
Tan wasn't the hitman. He was the original guy that ordered the hit. All the other guys, too (except the last), were acting as middlemen, ordering the hit and skimming some off the top. They were all requesting the murder of someone else by paying a 3rd party to do it.
