S23&Chrome,

Why is it so?

IMO local knowledge comes into play at country/provincial meetings,especially in Maiden races,more so if it,s trained at the track by a local trainer(of course).
If a horse has no form line yet is well in the market,take heed!
This horse had obviously shown the trainer something(in private)that the public had no knowledge of.
Was it ridden by an apprentice at when it ran 5th and a senior rider this time?
Your probably right about"mate's money"as the trainer most likely would let his mates know it was ready to do something,probably over a beer at the local watering hole.
Those mates then tell their mates and bingo,the money goes on and it opens up short.
I have a mate who swears by such bets in maiden races in the country only.
He also reckons that favs in country maidens have a good win/place s/r.
Maybe Wes could run some stats,it would be interesting to see the actual w/p s/r for such races.