I agree she ele, personally I don't believe the truth came out in this enquiry, I can't believe Gai didn't tell Tom more joyous was a non goer.  Andrew Johns was in fear of losing his job for channel 9, hence his lack of memory.

Of course he knew he confessed he laid off 300 grand (in a roundabout way) but would have held 10 times ( or more) that much on a beaten favourite

.... If he thought it had a chance to win he would have laid off much more

He made a big big  quid on that non information

When a bookie "lays off" imbalances, what he or she is doing is making a bet with another bookie, usually one who deals with a larger volume of wagers, either by tacit agreement with the bookie in question, or just by having one of their associates set up an anonymous wager.

If they have, say, a $1000 imbalance in favor of horse A, and they want to reduce their risk, they can make a wager for $1000 on Horse A, on the best terms they can get. If horse A wins, their own winnings cover the payout they will give to whomever represents that $1000 imbalance.

If horse A loses, they collect the losers' wagers, plus the vigorish, and (hopefully) pay less vig to the bookie they owe. Usually, they don't want to do this, since chances are that you break even or lose a little bit of money (since the upstream bookie probably sees the same trend in his wagers, he's likely to not give very good terms).

However, in some cases, it's unavoidable.