Sharking is one of those situations where a needle eye hook is much better than a ring eye for a couple of reasons. First off, there’s no doubt shark teeth will cut right through mono and in some cases cable. Single strand wire leader is definitely preferred for shark fishing for this very reason.
Secondly, there is a small finished connection to the hook with wire-to-a-needle-eye, and that connection is much smaller than with a ring eye. If you’ve ever had a run-off while sharking (and you were sure you set the hook) only to have the line go limp after a very short time, there’s a good sensible explanation for that.
Most likely the rig you were using was made using ring eye hooks. The shark picked up the bait and started to swim away with its mouth closed. When you locked up the reel to set the hook and with the sharks’ mouth closed the ring eye hook was so large it was just banging against the inside of its teeth, preventing the point of the hook from penetrating anything….you thought you had a good hook set but when he opened his mouth the bait and the hook just fell out.
Using a needle eye hook with its much smaller connection would have had a much better chance of going through the rows of teeth and giving you a solid hook set.