From Computer bets skew pick 3 (drf.com)

Calder racing officials said that an investigation into the pick three on Oct. 28 concluded that the robotic wagering system inadvertently sent in a series of pick three wagers in $31.74 denominations, rather than $1. As a result, the robotic system put $40,000 worth of wagers into the pool just seconds before the race started. The entire pool, including the IRG wagers, was $54,482, approximately four times the average pick three pool at Calder on a Saturday.

The payout for the pick three, which linked winners paying $7, $29.20, and $4.60, was $54.40, roughly one-quarter of the parlay price of $235. In addition, the total amount returned to all winning bettors barely exceeded the amount of money bet by the IRG customer. Calder has a 24 percent takeout on pick three pools, so after breakage, a maximum of $41,398 was distributed to winning bettors.

Even with the rebate these bets were losers. Why did the host system accept $31.74 wagers?