Agreed. We don't completely know the situation at all.....but like ShutUpJoe said, the mare wasn't in labor for very long. It is absolutely crazy to pull, pull, pull against the mare's contractions/pushes when there is nothing wrong with the foal or mare. A normal birth progresses naturally slow. That way the cervix can completely open slowly and the vagina can stretch little by little. One situation that I can see where getting that foal out as quickly as possible is a breech birth. I'd call my vet than pull with all my might, too. LOL.
We have VERY expensive Arabians. VERY. But, every birth is treated the same. The mares are scrutinized and monitored with a high level of care. I sleep right above them every night in an apartment, watching the foaling cameras on my TV (they have cameras in their stalls). And I'm ready to help with EVERY birth. No mare foals without our help.
BUT, we always take our time. Mares are allowed to get down and rest while they wait for their big contractions to push. They never lay down flat until they need to start getting the head out. We wait until then to help. By then, the mare is in the zone and won't (usually) get up when I open the stall door.
So I go in and gently GENTLY give a few soft tugs to help get the head in position and make sure everything is straight and ready. Then, the mare starts pushing hard and I'm right there to help her. When she stops pushing for a breather, I stop pulling. NO pulling when she is not pushing. That's how you tear her and make the birth more painful than it already is. Birth is a slow process. That cervix and vagina need time to stretch so they won't tear. I always match my level of intensity pull to the mare's push. If she's pushing with all her might, then I'm pulling hard. But I always release when she pauses.
After hundreds of births, I've had a wonderful time doing it this way. The mare does awesome and we have healthy births. Ne tearing, no stress (I'm always very calm) and the foal is delivered in a reasonable amount of time. There is no gigantic hurry.
I watched my first birth last week on MareStare and was soooo frustrated to see the people pulling with all their might .....when the mare wasn't even pushing. They acted like getting the foal out as quickly as possible was the only option. That's BAD.
Anyway, just my loooong post, 2 cents. LOL.
A good horse is worth more than riches. ~ Spanish Proverb