In Hawaii it is Now Illegal to Kill Sharks & Rays!
I fished this exact spot the day before. The next morning the place smelled. I recognized the scent as shark blood which is really stink. It only took less than a minute for me to figure out what happen. It may not have been on purpose just to kill a shark. But leaving the hook & wire leader told me whoever caught this shark wasn't an ethical angler.
A respectable angler wouldn't leave their wire leader in the open. Plus leaving a large hook for someone to step on. They left it there because they didn't care. Accidental hook-ups happen. But if it was by a responsible angler they'd clean-up their mess. If that happen to me not only would i throw the garbage away but i'd wash the stinky blood off as well. If you caught it you're fully responsible for your mess.
I know it was hooked the night before because i was here all day the day before. I left when it started to get dark. And i just got back the following morning.