A theoretical.
A top class in-form horse racing over a sprint distance from the inside of the Second Line in a hot 8 horse field....Horse A...Third Favourite..
The Pole Marker(Horse B...Hot Favourite)) flies out and after 200 metres there is speed duel that sees the Pole Marker and another horse(Horse C...outsider) outside it slip away from Horse A leaving a gap of 15 metres between the duellers and the horse in question.
After about 300 metres, Horse D..double figures slips around Horse A and heads to the markers to sit behind Horse B.
Horse A is now relegated to third on the markers but now there are no horses outside him in the running line and in fact the next horse in the running line is 6-10 metres back..
Any chance of using the Sprint Lane are greatly diminished and its only a short race.
Should Horse A pull out into the Running Line and get in behind the now relaxed Horse C?
And more to the point should the Driver of Horse A be carpeted for failure to show initiative?

200 Metres after the Start:
C... DXX
B....AXXX

300 metres after the Start:
C..... XX
BD.AXXX