Horse racing generally suspended late

I just lost 80 pounds because i was having some back bets in the market when the horse missed the start and somebody took the bets pre race...  they were 7,8 ticks from the traded price at the start, then 1 second before the suspension someone takes them, then a couple of seconds later i see on betfair video the horse missed the start and i have to trade out in-play for double the price...

this is a bit annoying because its not the first time i lose like this and makes my market making strategy too risky.

why is it betfairs policy to suspend the market just when the race start on betfair live video? Everyone knows people are 2-3 seconds ahead of this and your pre-race money is not protected.

so even it is not that obvious on every race apparently people on track or on a fast feed are backing/laying horses that start well/bad before the market goes in-play.

The horse im talking about was Essaka on the 2:45 Brighton race, i attached a screenshot so im not making this up.

Should pre-race bets not be protected from these poeple??