The draw sheet is posted at the race office.
The draw sheet will show all horses entered with their last race date.
I think all race offices would tell you that information.

He said it - said he did it - appears he did it - and it worked.

Will it work every time, maybe not.

4 heavily bet horses out of 6 there, was a smart move as it turned out.

You looking for new sparring partners 

Go put out 100wp wagers and prove your point.

He already did and it succeeded. 

Seriously, what's 200 bux to risk to challenge someone's integrity. 

Trainers make their money with a daily training bill. The 5% that they earn is not the basis of their income, not to mention the vast majority of trainers also own horses. They get purse money and their daily bill.

Skeptical--probably.  I can admit to that quite honestly!

However, there were better ways to invest that $ 200 to make more money besides the win-place bet.  Maybe 50-50 and spreading the other $100 on exactas and trifectas. 

I bet a horse at Tioga from the 9 hole at long odds last year!  Again, not a lot of money in the pool.  Any 'big bet'  [$100] would have resulted in a much lower payout on the amount being bet and stepping on my own $$$.  The more you bet on this type of ticket, the lower the payouts and ROI and increased risk.  FYI, the horse won and paid $ 49. 

You're betting into small track pools, not major tracks/Kentucky derby pools!