hmm well I suppose the default ruling should be how it currently is, but there are definitely enough people who want to use exact times, so MonkeyIsland can we include this in the rules? If both sides agree before the game, they can use exact times.
And now that I think about it more, if exact times are agreed upon, they should be truly exact --> meaning exactly when the worm animation changes touching the finish (so if a turn ends early with a head hit, you must add any extra time to your score). sure there is a little risk/reward using the early fall strat, but if we're truly wanting to be exact, it should be when the worm touches finish.