Goaline technology can be done low tech. The main problem is the ball ricocheting off the woodwork behind the line and back into play . If a sloped ( 10degree) energy absorbing material ( e.g. wet sand) was laid from half a ball width behind the goal line extending to the back of the goal then the spin and energy would be absorbed and deflected towards the back of the net. The only situation this would not cover would be when the ball crosses the line to hit a defender behind the line tobounce back seemingly into play.
