Largest Shark By Line When A Fisherman Wants To Reel A Large Dead Shark Hooked On A Thin Fishing Line?

When a fisherman wants to reel a large dead shark hooked on a thin fishing line? - largest shark by line

it will not draw the line, because it is broken, so that drums that gradually and smoothly, because it is run. Why? Can someone explain the laws of Newtonian motion.