OK, I understood, but in your example the sequence of bets is Back then Lay, whereas in your original description the first bet is Lay, and the profit from that bet already is on the favourite, because you lay the underdog.
Do you actually mean you want to back the underdog once the favourite ties?
Also, how do you intend to hedge (which selection by the way) if the favourite scores the second goal? There will be one back and one lay bet on the underdog and no bets on the favourite. So hedging per se is not applicable, but what can be done is shifting some of the profit from the underdog onto other selections.