Is the new Deworming Revolution for horses correct?

I have been reading about resistant strains of Equine internal parasites for some time now and have been confused because it goes against what I have found in Stamina Plus’s research facility here in Cody, Wyoming. This morning one of the research facility horses developed a colic episode related to a Strongyle worm infection. How do I know? After treating the colic with Banamine IV and starting the horse on oral Fiber Plus (4 ounces) I performed a microscopic stool exam and found 4+ Strongyle worm eggs. A 4+ is a lot of eggs and more than I normally see even in client horses. The horse responded very quickly and was back eating and normal in 20 minutes. Why did this horse colic from intestinal infection with Strongyles. I suspect that the irritation to the intestinal lining from the worms is what caused the colic. Now for 30 years in the research facility and with clients I have dewormed horses every 8 to 10 weeks and rotated during the year. When I have checked stool samples for worm eggs I have found very few eggs and also during that time have rarely diagnosed a worm colic. Recently I have found myself buying into the new research about over deworming and have started to deworm less frequently. The horse in question has not been dewormed for 4 months but has had monthly stool samples checked for worm eggs. Obviously the Strongyle eggs did not hatch until recently. This has always been my complaint about not worming until stool exams show a large amount of worm eggs. Strongyle worms have life cycles from eggs to adults that run from 3 months to 8 months and therefore what is most important is to not to contaminate pastures and pens with worm eggs and I have always believed that the best way to protect your horse from intestinal damage, colic and possible death is to deworm every 8 to 10 weeks and rotate wormers during the year.