Betfair act as the middleman apart from any trading they may do on their own markets but they would gain nothing by pursuing this kind of madness. They get the best information available - the money hitting the system - they see it before any of us!
This is down to people trying to beat the clock and making a horlicks of it. I have said many times, I wonder how long it can last because someone is losing a lot of money. I have heard rumours that some shady characters are laundering money but I have no proof of this.
There will also be PC payers looking to offset commission by laying/backing according to their position to generate commission and improve their account situation but again I do not know how much or for how long.
I have watched the markets for about 12-13 years and this has come full circle. When people were trading from the standard TV or pure odds the prices would trade low but it would need to be a tight finish. Then people became savvy about it and started to lay the field to take advantage. The market soon stopped that and it became very difficult to make it pay. I must add that never would a horse trade below 1.70-1.80 unless it looked close to winning.
Now we have clock beaters, people paying ££££s to trade with live pictures from hospitality boxes. I know plenty of them and they are NOT all making a living. I knew of a guy who thought he was invincible and bragged about vast sums he was making. He then lost £120,000 on four short priced horses all of which were beaten. It wiped him out and he lost everything.
At Taunton there was a horse that threw the jockey en route to the finish line. He was 100 yards out and had jumped all the fences to look a certain winner. The horse jinked left then right as if spooked and the jockey hit the deck. There was a group who lost around £500,000 on that one race because they were smashing it at all prices down to 1.01 and laying the supposed 2nd placed horse at 1000 too! Ouch that must've hurt!

I do not have the data on the amounts matched but I am sure someone on here does. There are some hefty sums being wagered at stupid prices which means someone is getting rich and someone else it getting poor. That is why I question how long it will continue. They say a fool and his money is soon parted but many will step up as replacements in the belief there is a pot of gold at the end of the rainbow. A lot of the guys I knew who considered themselves to be good race readers now don't have a pot to p**s in but they will always tell you they're killing it.
One last example, a very sad but true story. I went along to a "clock beating" session at the invitation of the guy who organised it. I have been to quite a few but this one always sticks in my mind. I sat next to a guy and watched him out of the corner of my eye. I was trading small amounts and making about £20-£25 per race, I was not trying to go mental. On one particular race I watched as a horse cruised up through the field into 3rd place. I knew the horse in question was a weak finisher, a real "bridle horse" and one to be wary of. The price was hammered into around 1.60 but with 2 fences to go and a stiff uphill finish I knew he would probably come under pressure at some point. Three of them jumped the penultimate fence and I had already laid if for £200 at 1.60 ready to bail if he did actually go through with it. Sure enough he found nothing and went out as if someone had shot him. There was a cry of anguish from the guy next to me and I could see he had backed this horse for around £18,000 at various prices from 2.0 down to the low of 1.34 only to find it finished 3rd!! He had other activity in the market but when the dust settled he had lost around £30,000 on that single race. He stormed out and returned about 30 minutes later, reloaded his account and carried on.
When the session was over we all went for a much needed drink. This guy was asked how he'd finished on the day. He said "I clawed most of it back and lost about £3,000 overall!" That was complete BS as I had seen him lose on several races and his biggest win was about £1500! Now I didn't know the guy personally but it was clear he was an out and out gambler who was deluding himself about his P&L. The money was from his redundancy and sadly I heard that after 6 months of clock beating he'd lost the lot! I am not writing this to berate him or anyone else I am simply saying some people will lose a lot of money and disappear without a trace only to be replaced by the next one looking for easy money.