Rubbish!! Collett only ever hit her once and the horse reacted.
Collett carried the whip in her right hand and the only movement was when she gathered the reins and changed the whip to her left hand before the strike.
Probably no need to use the whip either as she had Sweynesday covered.
I'm not convinced it was the sole reason but agree it could have been a factor.
Horses see white exceptionally well. Presumably running rails are white so horses can see them which begs the question - why change the colour for the last 100m to something harder for the horse to see?
No one can read the advertising on the rail anyway unless you are the Jockey on their way going through it.
Perhaps the irony is it is so the Stipes know when to count the number of whip strikes in the last 100m!!!!